middle school chemistry

7/29/2019 Middle School Chemistry

1/689

MIddle school cheMIstry


2/6892 Middle School Chemistry Unit 2011 American Chemical Society

Chapter 1, Lesson 1: Molecules Matter

Key Concepts

Chemisry is he sudy o mater.Mater is made up o exremely iny paricles called aoms and molecules.

Aoms and molecules make up he hree common saes o mater on Earhsolids,liquids, and gases.Te paricles o a liquid are atraced o one anoher, are in moion, and are able o movepas one anoher.Being a solid, liquid, or gas is a propery o a subsance.

Summary

Sudens discuss he meaning o chemisry and mater. Sudens invesigae a drop o waerhanging rom a dropper and drops o waer beading up on wax paper. Tey also look a a molecu-lar animaion ha models he moion o waer molecules. Sudens are inroduced o he idea

ha mater is made up o exremely iny paricles ha are atraced o one anoher.

Objective

Sudens will describe heir observaions abou waer on he molecular level using he idea hawaer is composed o iny molecules ha are atraced o one anoher.

Evaluation

Te aciviy shee will serve as he Evaluae componen o each 5-E lesson plan. Te aciviyshees are ormaive assessmens o suden progress and undersanding. A more ormal summa-

ive assessmen is included a he end o each chaper.

Saety

Be sure you and he sudens wear properly ting goggles.

Materials or Each Group

Waer in small cupDropper popsicle

Wax paper large index cards (5 8)ape

About this Lesson

You may be able o complee his lesson in less han class period. I you hink his will be hecase, you can move on o Lesson , which is an applicaion o he conceps covered in Lesson .

Materials or the Demonstration

all clear plasic cupWaer (room emperaure)Whie shee o paper

Food coloring (red, blue, or green)


3/6892011 American Chemical Society Middle School Chemistry Unit 3

Noe: Some solids, liquids, and gases are made o aoms, and some are made o molecules. Since heconceps covered in Chaper 1 apply o boh aoms and molecules, he erm paricle is used as a

generic erm o include boh. A his poin, i is enough o give sudens simple working deniions oaom and molecule. You can ell sudens ha an aom is he smalles building block o mater andha a molecule is wo or more aoms conneced ogeher. Le sudens know ha even hough aoms andmolecules are dieren, in Chapers 1 and 2, hey will boh be represened by circles or spheres. Chapers3 and 4 will go ino more deph abou he srucure o aoms and molecules and will use more deailedmodels o represen hem.

engage

hv iui bu mi m.1.

You could begin he rs class by leading a shor discussion. Ask sudens wha hey hinkhe sudy o chemisry migh be abou. You can ge a sense o suden prior knowledge,

ideniy some misconcepions, and jus ry o ge sudens on he same page.

ell sudens ha chemisry is he sudy o mater and wha mater does. You could go soar as o say ha chemisry is he sudy o su and wha su does on a very small scale.

Ask sudens or he hree common ypes o mater on Earh (solid, liquid, and gas).

Ask sudens quesions such as he ollowing o guide heir hinking:Wha are some examples o mater? ell sudens ha mater is oen dened as anyhing ha has mass and akes upspace. Coninue he discussion by using waer as an example.Does waer have mass, and does i ake up space?

A bucke o waer is prety heavy o li. I deniely has mass. I also akes up spacein he bucke. Since i has mass and akes up space, waer is mater. Bu has jus he

very beginning. In chemisry, we wan o look deeper and nd ou more abou whamater is made o and how i acs.

Give each suden an aciviy shee.

Sudens will record heir observaions and answer quesions abou heaciviy on he aciviy shee. TeExplain I wih Aoms & Molecules andake I Furhersecions o he aciviy shee will eiher be compleed asa class, in groups, or individually, depending on your insrucions. Looka he eacher version o he aciviy shee o nd he quesions andanswers.



explore

d ivi i w mu v .2.

In his aciviy, sudens look closely a a drop o waer and move drops o waer on waxpaper. Tey see ha he waer holds ogeher well and is no so easy o separae. Te goal

is or sudens o begin hinking abou waer, or any subsance, on he molecular level ando conclude ha waer molecules mus be atraced o one anoher. Te reason or heseatracions will be deal wih in laer chapers.

Quesion o invesigaeDoes waer hold ogeher well or come apar easily?

Maerials or each groupWaer in small cupDropper

popsicle sicksWax paper large index cards (5 8")ape

eacher preparaionCover a large index card wih a piece o wax paper so ha he

wax paper compleely covers he card. ape he wax paper inplace. Prepare wo cards or each group.

ProcedureUse he dropper o genly squeeze ou a drop o waer bu.ry no o le he drop all compleely ou o he dropper. Seehow ar you can make he drop hang o he end o he drop-per wihou he drop alling.

Place or 5 drops o waer ogeher on a piece o wax paper.o make one medium-size drop.

Genly il he wax paper in dieren direcions so ha he.

drop moves.Use a popsicle sick o slowly drag he drop around he wax.paper a bi. ry using your popsicle sick o separae yourdrop ino wo.

Use your popsicle sick o move he drops near each oher.5.Ten move one drop so ha he wo drops ouch.



3. r iu u bvi.

Give sudens ime aer he aciviy o record heir observaions by answering he ollow-ing quesions on heir aciviy shee. Once hey have answered he quesions, discuss heirobservaions as a whole group.

When you squeezed he drop o waer ou o he dropper, did he waer breakapar or did i hold ogeher?

When you iled he wax paper, did he drop spli apar or say ogeher?When you were pulling he drop around he wax paper, did he waer seem ohold ogeher or come apar easily?

When you ried o spli your drop, did he drop separae easily?Wha happened when he wo small drops ouched?

Expeced resuls

Te waer beads up on he wax paper and says ogeher when he wax paper is iled andwhen he drop is moved around wih a sraw. I is dicul o separae he drop ino wodrops. When he drops ouch, hey combine quickly and easily.

4. d mi w w mu i mi.

Maerialsall clear plasic cup

Waer (room emperaure)Whie shee o paper

Food coloring (red, blue, or green)

ProcedureAdd waer o he cup unil i is abou lled..

Ask sudens o wach closely as you add one or wo drops o ood coloring o he.waer. Do no sir. Insead, allow he color o slowly mix ino he waer on is own.

Hold he cup up wih a shee o whie paper behind i so i is easier or sudens o see.he color moving and mixing in he waer.

Expeced resulsTe drops o ood coloring will slowly move and mix ino he waer. Evenually all he

waer in he cup will be evenly colored.

Ask sudens:How do your observaions suppor he idea ha waer molecules are moving?Help sudens undersand ha he drop o coloring mixes ino he waer because he waer



molecules move and push he color in all direcions. Te molecules o he ood coloringhemselves are also in moion.

Noe: In chaper 5, sudens will learn ha waer molecules and coloring molecules are atracedo each oher. Tese atracions also help explain he mixing o he color in he waer.

explaIn

5. sw imi mu i iqui w.

Show he molecular model animaionParicles o a Liquid.www.middleschoolchemisry.com/mulimedia/chaper1/lesson1#paricles_o_a_liquid

Explain ha he litle balls represen he paricles o a liquid, in his case waer molecules.Le sudens know ha or now, hey will use circles or spheres o represen aoms andmolecules, bu evenually hey will use a more deailed model. For now, sudens shouldocus on he moion o he molecules, how hey inerac, and heir disance rom oneanoher.

Poin ou ha he molecules o a liquid are in moion bu hey are atraced o each oher.Tas why hey move pas each oher bu don ge very ar apar rom one anoher.

6. hv u w i w m w mu v m ivi .

Draw or projec he illusraion Waer Molecules.www.middleschoolchemisry.com/mulimedia/chaper1/lesson1#waer_molecules

Explain o sudens ha his is a model o waer mol-ecules. Poin ou ha he molecules are no in anyexac order bu are near each oher. Tey have litlecurved moion lines o show ha he molecules aremoving.

Have sudens draw a model o waer on he molecu-

lar level on heir aciviy shee. Tey should use hemodel you have shown hem o guide heir owndrawing.



Sudens drawings should show ha he molecules are:Randomly arrangedClose ogeherMoving

Be sure sudens realize ha his model shows waer molecules enor-

mously bigger han hey acually are. No only are waer moleculesmuch smaller, hey are also much more numerous. A single drop o

waer is made up o more han a billion rillion exremely iny waermolecules.

o give sudens an idea o how small and numerous waer molecules are, you could ellsudens he ollowing: In abou ablespoon o waer, here are abou 600 billion rillion

waer molecules. I you could coun million waer molecules every second, i would akeabou 00 million cenuries o coun all he molecules in ha ablespoon o waer. Aoms

and molecules are huge in number and incredibly small in size.

extend

7. sw vi u m w mu .

Show a video o a waer balloon popping in slow moion.www.middleschoolchemisry.com/mulimedia/chaper1/lesson1#waer_balloon

Ask sudens:Why do you hink he waer keeps is shape he momen he balloon is popped? Sudens should realize ha waer holds ogeher prety well because he waermolecules are atraced o each oher.Imagine a drop o waer hanging rom your nger. How is his similar o he

waer saying ogeher aer he balloon is popped?Tis can also be explained by he ac ha waer molecules are very atraced o eachoher.



extra extend

I u v im, iv u ui m wi 4.w.

Waer Drops Unie!

eacher PreparaionPrin Waer Drops Unie shees oreach group.

Procedureape a piece o wax paper over he.Waer Drops Unie shee.

Place abou 5 drops o waer in each.o he small circles around he ou-side.

As as as you can, use your sraw o drag each drop o waer o he cener. When all.he drops are unied in he cener, you are done.

Challenge your parner o see who can unie all heir waer drops he ases..

Race Drop Racewayeacher PreparaionPrin Race Drop Raceway shees or each group. You and a parner can ollow hedirecions below o race each oher.

Procedureape he Race Drop Raceway shee ono a piece o cardboard o give i suppor..

ape a piece o wax paper over he Race Drop Raceway shee..

Place drops o waer ogeher o make one larger drop a he Sar..

As as as you can, il he cardboard and guide your race drop around he rack o he.Finish. ry no o ouch he edge o he rack. Te rs o nish is he winner.



Activity Sheet Name: _________________Chapter 1, Lesson 1Molecules Matter Date: __________________

In the activity below, you will investigate some o the characteristics o water. Youwill also begin to model and explain, on the molecular level, why water acts theway it does.

Activity

Quesion o invesigaeDoes waer hold ogeher well or come apar easily?

Maerials or each group

Waer in small cup

Dropper popsicle sicks index cards covered wih wax paper

ProcedureUse a dropper o genly squeeze ou one drop o waer bu ry.no o le he drop all compleely ou o he dropper. See howar you can make he drop hang o he end o he dropper

wihou he drop alling.Place or 5 drops o waer ogeher on he wax paper o make a.

medium-size drop.Genly il he wax paper in dieren direcions so ha he drop.moves.Use a popsicle sick o slowly move your drop around he wax.paper. ry using your popsicle sick o separae your drop inowo.Use your popsicle sick o move he wo drops near each5.oher. Ten move one drop so ha he wo drops ouch.

WhAt did you observe?

When you squeezed the drop o water out o the dropper, did the1.water break apart did it hold together?



When you were pulling the drop around the wax paper, did the water seem to2.hold together or come apart easily?

When you tried to split your drop, did the drop separate easily?3.

Was it easy or dicult to make the drops come together?4.

demonstrAtion

Your teacher placed a drop o ood coloring in a cup o water. The color slowly5.mixed into the water without being stirred. What does this tell you aboutwater molecules?



explAin it With Atoms & molecules

You saw an animated molecular model o water. Now you will draw your ownmolecular model.

Using circles and motion lines to repre-6.sent water molecules, draw a model owater on the molecular level. Be sure toshow that water molecules are:

Randomly arranged.Close together because theyattract each other.Mov ing

What is it about water molecules that helps explain why the water drops7.were dicult to split apart but easy to join together?



tAke it further

In the video o the water balloon, you saw what happens in slow motionwhen a water balloon is popped. Surprisingly, there is a moment when thewater hangs in the air in a balloon-shape, ater the balloon has been popped.

Why do you think the water keeps its shape the moment the balloon is8.popped?

Imagine a drop o water hanging rom your nger. How is this similar to the9.water staying together ater the balloon is popped?



Chapter 1, Lesson 2: Molecules in Motion

Key ConceptsHeaing a liquid increases he speed o he molecules.

An increase in he speed o he molecules compees wih he atracion beweenmolecules and causes molecules o move a litle urher apar.

Cooling a liquid decreases he speed o he molecules.A decrease in he speed o he molecules allows he atracions beween molecules obring hem a litle closer ogeher.

SummarySudens add ood coloring o ho and cold waer o see wheher heaing or cooling aecs hespeed o waer molecules. Sudens wach molecular model animaions o see he eec o hea-ing and cooling on he molecules o a liquid. Sudens will also draw heir own molecular model.

ObjectiveSudens will be able o explain, on he molecular level, ha heaing and cooling aec molecularmoion.

EvaluationTe aciviy shee will serve as he Evaluae componen o each 5-E lesson plan. Te aciviyshees are ormaive assessmens o suden progress and undersanding. A more ormal summa-ive assessmen is included a he end o each chaper.

Saety


Materials or Each Group

Ho waer (abou 50 C) in a clear plasic cupCold waer in a clear plasic cup

Yellow ood coloring in a small cupBlue ood coloring in a small cup droppers

engage

ak u u i im i w1.mu i i i w m w.

Ask sudens quesions such as he ollowing:Is he speed o waer molecules dieren in ho and cold waer? Wha can we doo nd ou?



Sudens may guess ha molecules in ho waer move aser. Tere are several pos-sible experimens ha sudens migh sugges o nd ou i his is rue. One o hemore obvious ones is o hea waer a lo so ha i boils. Ten you can see he waermoving. You could do ha bu i requires a ho plae, akes a air amoun o ime,and may have o be done as a demonsraion insead o being an aciviy he su-dens can do.

ell sudens ha one possible mehod is o use ho waer and cold waer and add oodcoloring o he waer. I he waer molecules move aser a one emperaure han anoher,he ood coloring should move aser oo and make he movemen easy o see.

Ask sudens:Should we use he same amoun o ho and cold waer in our experimen? YesShould we use he same ype o cup or he ho and cold waer? YesShould we use he same number o drops o ood coloring in each cup? YesShould we pu he coloring in a he same ime? Yes

Explain ha he dieren hings like he amoun o waer, ype o cup, and number odrops o ood coloring are called variables. I is imporan o keep all he variables hesame excep or he one you are esing. Because we are rying o nd ou iemperaureaecs he moion o waer molecules, we should keep everyhing else abou he experi-men he same. emperaure should be he only variable. Tis way, i we noice somehingdieren beween he wo samples o waer, we will know ha he dierence in empera-ure is causing i.

Give each suden an aciviy shee.Sudens will record heir observaions and answer quesions abou heaciviy on he aciviy shee. TeExplain I wih Aoms & Molecules andake I Furhersecions o he aciviy shee will eiher be compleed asa class, in groups, or individually depending on your insrucions. Looka he eacher version o he aciviy shee o nd he quesions andanswers.

explore

d ivi m w mu i 2. w.

Quesion o invesigaeIs he speed o waer molecules dieren in ho and cold waer?



eacher preparaionTis aciviy works bes i here is a big dierence beween he emperaures o he hoand cold waer.

Squir 5 drops o blue ood coloring ino a small cup or each group..

Squir 5 drops o yellow ood coloring ino anoher small cup or each group..

Add ice o abou 6 cups o ap waer o make i sucienly cold..Pour abou cup o cold waer (no ice) ino a cup or each group..

Pour abou cup o ho waer ino a cup5.or each group.

Maerials or each groupHo waer (abou 50 C) in a clearplasic cupCold waer in a clear plasic cup

Yellow ood coloring in a small cupBlue ood coloring in a small cup droppers

ProcedureWih he help o your parners, use droppers o careully place drop o yellow and .drop o blue ood coloring ino he ho and cold waer a he same ime.

Allow he colors o mix on heir own as you wach hem or a couple o minues..

3. r iu u bvi.

Give sudens ime aer he aciviy o record heir observaions byanswering he ollowing quesions on heir aciviy shee. Once heyhave answered he quesions, discuss heir observaions as a wholegroup.

Describe wha he colors looked like and how hey moved and mixed in he coldwaer.Describe wha he colors looked like and how hey moved and mixed in he ho

waer.Wha does he speed o he mixing colors ell you abou he speed o he mol-ecules in ho and cold waer?



Expeced resulsTe yellow and blue ood coloring will spread aser in ho waer han in cold. Te colors

will combine and urn green in he ho waer while he colors will remain separae longerin he cold waer. Sudens should agree ha he colors mix aser in he ho waer becausehe molecules o boh he waer and ood coloring move aser in ho waer han hey doin cold waer.

explaIn

4. sw imi w mu imu.

Show he molecular model animaionHeaing and Cooling a Liquid.www.middleschoolchemisry.com/mulimedia/chaper1/lesson2#heaing_and_coolingMove he slider a he botom o he window all he way o he righ o show ha he waer

molecules are moving aser and are a litle arher apar in ho waer.

Explain ha he litle balls represen he paricles o a liquid, in his case waer molecules.Le sudens know ha or now, hey will use circles or spheres o represen aoms andmolecules, bu evenually hey will use a more deailed model. For now, sudens shouldocus on he moion o he molecules, how hey inerac, and heir disance rom oneanoher.

Ask sudens:Are he molecules moving aser in cold or ho waer? Sudens should realize ha he molecules o ho waer are moving aser. Te mol-ecules o cold waer are moving slower.How does his mach wih your observaions wih he ood coloring? Te ood coloring in he ho waer mixed aser han he coloring in he cold waerdid.Look closely a he space beween he molecules in cold and ho waer. Is heremore space in beween he molecules in ho waer or in cold waer? Is i a lo ospace?Poin ou o sudens ha molecules o ho waer are moving aser and are slighlyurher apar. Te molecules o cold waer are moving slower and are a litle closerogeher. I sudens do no noice a dierence, move he slider all he way o he leagain and hen quickly o he righ. Show he animaion a ew imes o give sudensa chance o noice he dierences.



5. hv u w qui bu imi w m w mu i ivi .

Have sudens ll in he blank wih he word increases or decreases onheir aciviy shee as you read each senence.

Heaing a subsance increases molecular moion.

Cooling a subsance decreases molecular moion.As molecular moion increases, he space beween molecules increases.As molecular moion decreases, he space beween molecules decreases.

Projec he image Waer Molecules a Dieren emperaures.www.middleschoolchemisry.com/mulimiedia/chaper1/lesson2#waer_molecules_a_dier-en_emperaures

Have sudens reer o he drawing o room-emperaure waer on

heir aciviy shee and discuss how hey should represen he mol-ecules in cold and ho waer.

Cold waerAsk sudens:

Would he waer molecules be closer ogeher orurher apar? Sudens should draw he circles a litle

closer ogeher han he circles in he room-emper-aure waer. Te waer molecules are closer ogeher

because he slower moion allows he atracions obring he molecules a litle closer ogeher.Would here be more or ewer moion lines? Sudens should realize ha since he molecules in hecold waer are moving slower, hey should have ewermoion lines han he molecules in room-emperaure waer.



Ho waerAsk sudens:

Would he waer molecules be closer ogeher orurher apar?Sudens should draw he circles a litle urher aparhan he circles in he room-emperaure waer. Teaser moion compees wih he atracions waer mol-ecules have or each oher and causes he molecules omove a litle urher apar.

Would here be more or ewer moion lines? Sudens should realize ha since he molecules in ho

waer are moving aser han in cold or room-empera-ure waer, hey should draw more moion lines.

extend6. hv u i w w k u m

m-mu w.

Have sudens read and discuss he ake I Furherquesion on heaciviy shee. Aer he class discussion, have sudens wrie heir ownresponse o he ollowing quesion in he space provided on he aciviy shee.

Les say ha you measure exacly 100 milliliers o waer in a graduaed cylin-der. You hea he waer o 100 C and noice ha he volume increases o 104milliliers. Using wha you know abou he atracions beween waer moleculesand he way heaing aecs molecular moion, explain why he volume o waerin he cylinder increases when i is heaed.Sudens should realize ha he molecules in ho waer move slighly urher apar,accouning or he increased volume.



Activity Sheet Name _______________________Chapter 1, Lesson 2Molecules in Motion Name _______________________

ActivityQuesion o invesigaeIs he speed o waer molecules dieren in hoand cold waer?

Maerials or each groupHo waer in a clear plasic cupCold waer in a clear plasic cup

Food coloring (yellow and blue)

droppers

ProcedureWih he help o your parners, use droppers o careully place drop o yellow and drop.o blue ood coloring ino he ho and cold waer a he same ime.

Allow he colors o mix on heir own as you wach hem or a couple o minues..


Describe what the colors looked like and how they moved and mixed in the1.cold water.

Describe what the colors looked like and how they moved and mixed in the2.hot water.

What does the speed o the mixing colors tell you about the speed o the3.molecules in hot and cold water?



There were several variables in this experiment:4.

Amount o water in each cupType o cup usedNumber o drops o ood coloring

When the coloring was added to the water

Pick one o these variables and explain why you made sure it was kept thesame in the two cups.


You saw an animation o water molecules being heated and cooled. Now youcan draw your own molecular model.

Based on your observations and the animations, ll in the blanks with the5. words increases or decreases.

Heating a substance ______________________molecular motion.Cooling a substance ______________________molecular motion.

As molecular motion increases, the space between molecules____________.

As molecular motion decreases, the space between molecules ___________.

Using circles to represent water molecules, draw a model o the molecules in6.cold and hot water.

Use motion lines to show the speed o the molecules.Consider the space between molecules in each temperature o water.



tAke it further

Lets say that you measure exactly 100 milliliters o water in a graduated cylinder.You heat the water to 100 C and notice that the volume increases to 104 milliliters.

Using what you know about the attractions between water molecules and7.the way heat aects molecular motion, explain why the volume o water in

the cylinder increases when it is heated.


24/689



engage

Fi u w u kw bu mm.1.

Hold up an alcohol hermomeer and ask sudens:Why do you hink he liquid in a hermomeer moves up and down when i is

heaed and cooled?Sudens should realize ha he movemen o he liquid in a hermomeer is relaedo he moion o he molecules o he liquid when hey are heaed and cooled.Remind sudens ha molecules move aser and a litle urher apar when heyare heaed. Molecules also move slower and a litle closer ogeher when hey arecooled.

ell sudens ha hey will apply heir undersanding o wha happens when liquids areheaed and cooled o explain how a hermomeer works.


explore

d ivi ivi w mk iqui i 2.mm u w.

Quesion o invesigaeWha makes he liquid in a hermomeer go up anddown?

Maerials or each groupSuden hermomeer

Magnier

Cold waerHo waer (abou 50 C)



Procedure

A. Look closely a he pars o a hermomeer.Look closely a your hermomeer. Te liquid inside is.probably a ype o alcohol has been dyed red.

Pracice reading he emperaure in C by having your eye.

a he same level as he op o he redliquid. Wha is he emperaure?

Use a magnier o look closely a he her-.momeer rom he ron and rom he side.Look a he bulb and he hin ube haconains he red liquid.

Pu your humb or nger on he bulb and see.i he red liquid moves in he hin ube.

B. Observe he red liquid in he hermomeer when i is heaed and cooled.Place he hermomeer in ho waer and wach he red5.liquid. Keep i in he ho waer unil he liquid sopsmoving. Record he emperaure in C.

Now pu he hermomeer in cold waer. Keep i in he6.cold waer unil he liquid sops moving. Record heemperaure in C.

Expeced resulsTe red liquid goes up in ho waer and down in cold waer.Sudens will have an opporuniyo relae hese observaionso an explanaion, on he molecular level, o why he liquidmoves he way i does.

I you have ime, you can have sudens pick a emperaure somewhere beween he em-peraure o cold waer and howaer and hen atemp o combine an amoun o ho andcold waer o achieve ha emperaure in one ry. Tey can see how close hey can ge.

3. r iu u bvi.




Based on wha you know abou he way molecules move in ho liquids, explain why.he liquid in he hermomeer goes up when heaed.

Based on wha you know abou he way molecules move in cold liquids, explain why.he liquid in he hermomeer goes down when cooled.

Why do you hink he ube ha conains he red liquid is so hin?.

Wha do you hink is he purpose o he larger ouer ube?.

When heaed, he molecules o he red liquid inside he hermomeer move aser. Tismovemen compees wih he atracions he molecules have or each oher and causes hemolecules o spread a litle urher apar. Tey have nowhere o go oher han up he ube.

When he hermomeer is placed in cold waer, he molecules slow down and heir atrac-ions bring hem a litle closer ogeher bringing hem down he ube. Te red liquid isconained in a very hin ube so ha a small dierence in he volume o he liquid will benoiceable. Te large ouer ube has wo purposeso proec he ragile inner ube and

ac as a magnier o help you beter see he red liquid.

explaIn

4. sw imi mu iqui i mm .

Note:Alcohol molecules are composed o dieren aoms, bu in hemodel shown in he animaion he molecules are represened as simple red spheres.

Show he molecular model animaion Heaing and Cooling a Termomeer.www.middleschoolchemisry.com/mulimedia/chaper1/lesson3#heaing_and_cooling_a_hermomeerPoin ou ha when he hermomeer is heaed, he molecules move aser, ge slighlyurher apar, and move up he ube. When he hermomeer is cooled, he moleculesmove more slowly, ge closer ogeher, and move down he ube. Help sudens realizeha he atracions he molecules in he hermomeer have or each oher remain hesame wheher he hermomeer is heaed or cooled. Te dierence is ha when heaed,he molecules are moving so as ha he movemen compees wih he atracions, caus-

ing he molecules o move urher apar and up he ube. When cooled, he movemen ohe molecules is slower and does no compee as much wih he atracions he moleculeshave or one anoher. Tis is why he molecules in he hermomeer move closer ogeherand down he ube.



Ask sudens:Te animaion shows ha he molecules spread ou slighly

when heaed. Do you hink he hermomeer would workas well i he ube o red liquid were wider?Te molecules spread ou in all direcions when heaed. I heube were wide, he molecules would be ree o spread ou sideways as well asup. In he hin ube, he molecules can move very ar sideways, so hey go up. Tiscauses a greaer dierence in he heigh o he liquid, which is easier o see.

hv u w mu m mu 5.iqui i mm.

Projec he imageMolecules in a Termomeer.www.middleschoolchemisry.com/mulimedia/chaper3/lesson1#molecules_in_a_hermomeer

In he drawing, lines have been added o indicae he level o he liquidin each ube. In realiy, here is no line. Te line is made up o mol-ecules. Sudens should draw circles represening molecules all he wayup o he line drawn in each ube.

Have sudens use he projeced illusraion as a guide as hey draw a model o he mol-ecules in a ho and cold hermomeer on heir aciviy shee.

Te Ho Termomeerillusraion should show random circles wih more moion lines.Te circles should be a litle urher apar han in he cold hermomeer.

Te Cold Termomeershould show random circles wih ewer moion lines. Te circlesshould be a litle closer ogeher han he circles in he ho hermomeer.



extend

diu wi u w mm wi i iqui i m i6. i i v m mu.

Projec he imageDieren Termomeers Same emperaure.

www.middleschoolchemisry.com/mulimedia/chaper1/lesson3#dieren_hermomeers_same_emperaureell sudens ha his picure shows wo her-momeers ha are idenical in every way, excepone has alcohol and he oher has mercury inside.Poin ou ha boh hermomeers are placed inho waer ha is 00 C. Te levels o he alcoholand mercury are shown.

Ask sudens:How can he liquids in he hermomeers

be a dieren levels even hough hey arein waer ha is he same emperaure?

Hin: Alcohol and mercury are boh liquids bu are made odieren aoms and molecules. Use wha you know abou hemoion and atracions he paricles in a liquid have or oneanoher o explain why he levels o alcohol and mercury in hehermomeers are dieren.

Te main reason why he level o liquid in each hermomeer is dieren is ha heyare dieren subsances wih dieren properies. Te molecules ha make up healcohol have dieren atracions or each oher han he aoms ha make up hemercury. Tereore, heaing and cooling hem are going o make hem move dier-en disances up or down he ube.

Aer he class discussion, have sudens wrie heir own response o he quesion abouhe wo dieren hermomeers on he aciviy shee.

extra extend

I u v im mi, iv u ui mk7. i w mm.

Maerials or each groupes ube, abou 0 mLIsopropyl rubbing alcohol, 9%



Small cup small disposable waer botles (8 oz.)Food coloringParalmTin ransparen sraw (eiher cu rom a dropper or rom a Capri Sun drink)Ho waer (abou 50 C)Ice waer

eacher preparaionPlace an amoun o isopropyl alcohol ha will compleely ll a esube ino a small cup or each group. Add drop o red ood coloringo he alcohol. Genly swirl o mix.Use scissors o cu he bulb end o o a dropper. Ten cu diagonally on one end ogive he sraw a sharp poin. Insead, you may use a hin sraw rom a Capri Sundrink.

ProcedureCareully pour he colored alcohol ino he es ube so.ha he ube is almos compleely ull.

Wih he help o a parner, srech a small piece o paralm.over he op o he es ube so ha i is well-sealed.

While holding he paralm igh wih one.hand and he sraw in he oher, careullypierce hrough he plasic so ha he srawgoes ino he alcohol. Abou cenime-ers o sraw should sick ou o he op ohe plasic. Tis is your hermomeer.

Pour ice waer ino one waer botle unil i.is abou / ull.

Ask your eacher o pu ho waer in anoher5.waer botle so i is abou / ull.

Careully lower he es ube ino he ho waer.6. Wach he sraw above he plasic or abou min-ue.

Ask sudens o predic wha will happen when he7.warm es ube is placed in cold waer.

Careully lower he warm es ube ino he cold waer.8.Wach he sraw above he plasic or abou minue.



Suden research abou hermomeersSudens have seen ha adding energy o a liquid increases he moion o he moleculesand causes hem o spread a litle urher apar. Tey have also seen ha his movemenis he basis or how a hermomeer works. Inroduce he idea ha measuring emperaure

wih a hermomeer gives us an idea o he average energy o a subsance. Tis is an oppor-uniy or sudens o research dieren ypes o hermomeers, he hisory o hermom-eers, and how hermomeers are made and calibraed.



Activity Sheet Name _______________________Chapter 1, Lesson 3The Ups and Downs o Thermometers Date ________________________

Activity

Quesion o invesigaeWha makes he liquid in a hermomeer go up and down?

Maerials or each groupSuden hermomeerMagnierCold waerHo waer (abou 50 C)

Procedure

A. Look closely a he pars o he hermomeer.

Look closely a your hermomeer. Te liquid inside is prob-.ably a ype o alcohol has been dyed red.

Read he emperaure in C by having your eye on he same.level as he op o he red liquid. Wha is he emperaure?

Use a magnier o look closely a he hermomeer rom he. ron and rom he side. Look a he bulb and he hin ubeha conain he red liquid.

Pu your humb or nger on he red bulb and see i he red.liquid moves in he hin ube.

B. Observe he red liquid in he hermomeer when i is heaed and cooled.

Place he hermomeer in ho waer and wach he red liquid..Keep i in he ho waer unil he liquid sops moving.

Record he emperaure in C. _______

Now pu he hermomeer in cold waer. Keep i in he cold.waer unil he liquid sops moving.

Record he emperaure in C. _______




Based on what you know about the way molecules move in hot liquids,1.explain why the liquid in the thermometer goes up when heated.

Based on what you know about the way molecules move in cold liquids,2.explain why the liquid in the thermometer goes down when cooled.

Why do you think the tube that contains the red liquid is so thin?3.

What do you think is the purpose o the larger outer tube?4.


You saw an animated molecular model o a thermometer at dierent temperatures.Now you will draw your own model.

The drawing shows two close-ups o a thin tubein a thermometer like the one you used. Onepicture represents the thermometer in hot water,while the other is the thermometer in cold water.

Based on what you know about the motion5. o molecules in a liquid and what you sawin the animations, draw circles to repre-sent alcohol molecules in the liquid in thethermometer. Try to show the dierence indistance between the molecules when theliquid is hot and cold. Use motion lines torepresent their movement (ast or slow).



tAke it further

Imagine that you have two thermometers that are identical in every way,6.except one has alcohol and the other has mercury inside. Each thermometeris placed in hot water that is 100 C. The levels o the alcohol and mercury are

shown in the picture.

Why do you think the liquids in the thermometers are at dierent levels eventhough they are in water that is the same temperature?

hi: Alcohol and mercury are both liquids but are made o dierent atomsand molecules. Use what you know about the motion and attractions theparticles in a liquid have or one another to explain why the levels o alcoholand mercury in the thermometers are dierent.



Chapter 1, Lesson 4: Moving Molecules in a Solid

Key ConceptsIn a solid, he aoms are very atraced o one anoher. Te aoms vibrae bu say in xedposiions because o heir srong atracions or one anoher.Heaing a solid increases he moion o he aoms.

An increase in he moion o he aoms compees wih he atracion beween aoms andcauses hem o move a litle urher apar.Cooling a solid decreases he moion o he aoms.

A decrease in he moion o he aoms allows he atracions beween aoms o bring hema litle close ogeher.

SummarySudens will see a demonsraion wih a meal ball and ring showing ha hea causes aoms ospread a litle urher apar. Tey will also see ha cooling a solid causes he aoms o ge a litle

closer ogeher. Te same rules hey discovered abou liquids also apply o solids.ObjectiveBased on heir observaions sudens will describe, on he molecular level, how heaing andcooling aec he moion o aoms in a solid.


SaetyBe sure you and he sudens wear properly ting goggles.

Materials or the DemonstrationBall and ring designed specically or his demonsraion]Bunsen burner or heaing he ballRoom-emperaure waer (o cool he ball)

Notes about the materialsTe meal ball and ring is available rom Sargen Welch (WL66-0) or Flynn Scienic

(AP90) or oher suppliers.

About this LessonTe solid explored in his lesson is a meal. Meal is composed o individual aoms insead omolecules like in he waer and alcohol sudens learned abou in Lessons . Alhough aomsand molecules are dieren, we will represen aoms he same way we represened molecules,using a circle or sphere. Tis simple represenaion will help sudens ocus on he moion andposiion o he paricles when hey are heaed and cooled.



engage

rviw w u v iv bu mu i iqui 1.iu w m i mi i, .

Ask sudens:

Wha do you know abou he molecules in a liquid?

Be sure sudens undersand ha he molecules in a liquid are atraced o eachoher bu are able o move pas each oher.How does heaing or cooling aec he speed o he molecules and he disance

beween hem?Heaing speeds up he moion o molecules and cooling slows hem down. Wevealso seen ha speeding he molecules up makes hem move a litle urher apar andslowing hem down allows hem o move a litle closer ogeher.

Ask sudens i hese saemens also apply o solids:Do you hink he aoms in a solid are atraced o each oher? Sudens will probably realize ha he aoms o a solid are atraced o each oher.Explain ha his is how a solid says ogeher.Do you hink heaing or cooling a solid migh aec he moion o he aoms? Sudens should realize ha i you hea a solid, he aoms or molecules move aserand move urher apar. I you cool a solid, he molecules move more slowly andmove a litle closer ogeher.

sw imi u m m 2.mu i i iqui.

Explain ha he litle balls represen he paricles o a solid, in hiscase he aoms in a meal. Alhough aoms and molecules are dier-en, his same simple model o balls is used or boh. Le sudens know ha or now, hey

will use circles or spheres o represen aoms and molecules, bu evenually hey will use amore deailed model. ell sudens ha hey should ocus on he moion o he molecules,how hey inerac, and heir disance rom one anoher.

Show he molecular model animaionParicles o a Solid.www.middleschoolchemisry.com/mulimedia/chaper1/lesson4#paricles_o_a_solid

Poin ou he ollowing abou solids:Te paricles (aoms or molecules) are atraced o each oher.Te paricles (aoms or molecules) vibrae bu do no move pas one anoher.Te solid reains is shape.



Show he molecular model animaion Comparing Solid and Liquid.www.middleschoolchemisry.com/mulimedia/chaper1/lesson4#comparing_solid_and_liquid

Click on boh abs and make sure sudens noice he dierences in hemovemen o he aoms and molecules.

Te aoms in a solid are so atraced o each oher ha heyvibrae and don move pas each oher.Te molecules o a liquid are atraced o each oher, bu movemore reely and pas one anoher.


Sudens will record heir observaions and answer quesions abou he animaion on he aciviyshee. TeExplain I wih Aoms & Molecules and ake I Furhersecions o he aciviy shee willeiher be compleed as a class, in groups, or individually depending on your insrucions. Look ahe eacher version o he aciviy shee o nd he quesions and answers.

explore

d mi w i m w i i 3. w .

I is harder o show ha he paricles o a solid move aser when heaed han i is o showhe same hing wih a liquid like in Lesson . Bu you can do i i you have a special balland ring apparaus ha shows he expansion o a meal when heaed. Tis inexpensive

device, available hrough science educaion equipmen companies, consiss o a rod wiha meal ball on he end and anoher rod wih a meal ring. A room-emperaure, he balljus barely s hrough he ring. Bu when he ball is heaed sucienly, i will no passhrough he ring. I you do no have his equipmen, you can show sudens a video o hisdemonsraion iled Heaing and Cooling a Meal Ball.

www.middleschoolchemisry.com/mulimedia/chaper1/lesson4#heaing_cooling_meal_ball

Quesion o invesigae

How do heaing and cooling aec a solid?

Maerials or he presenerBall and ring designed specically or his demonsraionBunsen burner or heaing he ballRoom-emperaure waer (o cool he ball)



Procedure

A. Heaing he meal ballHold he ball in one hand and he ring in he oher..Show sudens how he ball s hrough he ring.

Place he meal ball in he fame o a Bunsen burner.

or abou minues.ry o push he ball hrough he meal ring again..

Expeced resulsTe ball will no hrough he ring.

Ask sudens:Why won he ball hrough he ring? Sudens should iner ha he speed o he aoms in he

meal ball has increased. Tis increased moion com-pees wih he atracions he aoms have or each oher,causing he aoms o move slighly urher apar. Tis is

why he heaed ball is oo big o hrough he ring.

When sudens see ha he ball expands, hey maywonder i he aoms hemselves expanded. ell sudens ha he aoms do no exp-land. Insead, he aoms in a solid ollow he same rules as he molecules in a liquid.Heaing increases molecular moion, causing he

aoms o spread a litle urher apar.B. Cooling he meal ball

Ask sudens:Wha could we do o he meal ball o make i hrough he ring again?Sudens should sugges cooling he ball.

Dip he ball in room-emperaure waer..

Push he ball hrough he meal ring.5.

Expeced resulsTe ball will hrough he ring.

Ask sudens:Why does he ball hrough he ring now? Sudens should iner ha he aoms slow down enoughso ha heir atracions pull hem closer ogeher, makinghe ball smaller so ha i can hrough he ring.



explaIn

4. sw imi i w m i m b i w .

Show he molecular model animaionHeaing and Cooling a Solid.

www.middleschoolchemisry.com/mulimedia/chaper1/lesson4#heaing_and_cooling_a_solid

Poin ou ha when meal is heaed, he aoms move aser and move slighly urherapar. Tis makes he heaed ball expand, which prevens i rom passing hrough he ring.

Poin ou ha when he meal is cooled, he aoms move slower and move slighly closerogeher. Tis makes he cooled meal ball ge slighly smaller so ha is hrough he ring again.

Give sudens ime o complee he quesions and drawings on heaciviy shee abou heaing and cooling he meal ball.

Projec he imageMolecules in a Room-emperaure and Ho Meal Ball.Help sudens draw circles o represen he aoms in he ball a room-emperaure andaer i is heaed. Have sudens wrie capions describing he speed and disance o heaoms in each picure.

extend5. hv u w v bu i i

i i w bi v ib i.

Show sudens he picure o he fexible connecion in he road on a bridge. Explain hahe surace o he bridge ges colder in winer and hoter in summer han he road oneiher end o he bridge. Tis is because he bridge is compleely surrounded by cold air inhe winer and by ho air in he summer. I is no insulaed by he ground beneah i.



Ask sudens:Knowing wha you do abou how solids ac when hey areheaed and cooled, why do you hink hey pu fexible connec-ions in he surace o a bridge?

Sudens should realize ha i he bridge is hoter han he land around i, i shouldbe able o expand a bi wihou breaking. I i is colder han he land around i, ishould be able o conrac a bi wihou breaking.

Aer he class discussion, have sudens wrie heir own response o he quesion abou

fexible bridge connecions on he aciviy shee.



Activity Sheet Name _______________________Chapter 1, Lesson 4Moving Molecules in a Solid Date ________________________


Ater you watch the molecular model animations o liquids and solids, answer thequestions below.

How is the motion o the atoms in solid metal dierent rom the motion o1.the molecules in liquid water?

What is it about atoms and molecules in liquids and solids that keep them2.close to one another even though they are moving?

demonstrAtion

At room-temperature the metal ball t through the3.ring. What happened when your teacher tried topush the heated ball through the ring?

What happened to the atoms in the heated metal4.

ball so that it didnt t through the ring?



Ater the ball was cooled by putting it in the water,5.why do you think it t through the ring again?


You saw in the animation that atoms in a solid move aster and get slightly ur-ther apart when heated. You also saw that they slow down and get slightly closertogether when cooled. Use this inormation to make your own drawing on themolecular level o the metal ball.

Draw a model o the atoms in the metal ball at room-temperature and ater6.it has been heated. Use circles and motion lines to show the speed and spac-ing o the atoms in the room-temperature ball. Include captions like atomsaster and urther apart or atoms slower and closer together to describeyour drawings



tAke it further

Look at the picture o the road o a bridge. The road on a bridge gets colder in thewinter and hotter in the summer than the road leading to it and away rom it.Many bridges have a fexible connection like the one shown in the picture.

Knowing what you do about how solids act when they are heated and cooled,7.why do you think they put fexible connections in the road on a bridge?



Chapter 1, Lesson 5: Air, Its Really There

Key ConceptsIn a gas, he paricles (aoms and molecules) have weak atracions or one anoher. Teyare able o move reely pas each oher wih litle ineracion beween hem.Te paricles o a gas are much more spread ou and move more independenly comparedo he paricles o liquids and solids.

Wheher a subsance is a solid, liquid, or gas a a cerain emperaure depends on he bal-ance beween he moion o he paricles a ha emperaure and how srong heir atrac-ions are or one anoher.Heaing a gas increases he speed o is aoms or molecules.Cooling a gas decreases he speed o is aoms or molecules.

SummarySudens compare he mass o a baskeball when i is defaed and aer i has been infaed. Te

infaed ball has he greaer mass, so sudens can conclude ha gas is mater because i has massand akes up space. Ten sudens consider how heaing and cooling aec molecular moion ingases. Tey dip he mouh o a botle in deergen soluion and observe a bubble growing andshrinking when he botle is warmed and cooled. Sudens will learn ha he atracions beweenhe paricles o gases are weak compared o he atracions beween he paricles o liquids orsolids.

ObjectiveSudens will be able o describe gas as mater. Tey will also be able o describe, on he molecu-

lar level, he eec o heaing and cooling on he moion o molecules o a gas.


Saety


Sudens should use care when handling ho ap waer.

Materials or Each Group clear plasic cups8-oz plasic botleDeergen soluion in a cupHo waer (abou 50 C)Cold waer

Materials or the DemonstrationBaskeball, very defaedBalance ha measures in gramsPumpCan o compressed gas (available a anyoce supply sore)



engage

diu wi u w ik i m.1.

Ask sudens abou gases:Are gases, such as he gases in air, mater?

Sudens may have quesions abou wheher or no gases are mater. Tey may alsohave only a very vague sense o wha gases are a all. Aer sudens reply, explainha he air around hem is made up o some dieren gasesnirogen, oxygen,carbon dioxide, waer vapor, and very small amouns o some ohers. ell sudensha gases are made o molecules bu ha he molecules are much urher apar hanhe molecules in liquids or solids. Since he molecules o a gas have mass and akeup space, gas is mater.

I sudens have rouble acceping or appreciaing ha a gas is made up o molecules, you

could ry helping hem by giving hem some numbers o hink abou. Alhough hesenumbers are huge and may be dicul o comprehend, a leas sudens will ge he ideaha a gas is deniely made o somehing, akes up space, and has mass. ell sudens hain an amoun o air abou he size o a sandard beach ball, here are abou 6 0 gasmolecules. Tis is abou 600 billion rillion molecules.

Sudens may have diculy imagining ha gases have mass. I seems like balloons andbeach balls, or example, ge ligher when we infae hem. When you add air o a bal-loon or beach ball i acually ges a litle heavier. Te reason why i seems ligher is no

because i has less mass, bu because is volume increases so much when i is infaed. Tisbig increase in volume wih a small increase in mass makes he balloon or beach ball lessdense. Ta is why i seems ligher when i is infaed. (Well ge o his when we sudydensiy in Chaper .)

d mi w m.2.

You will need a balance ha measures in grams or eiher demonsraion.I you don have his ype o balance, you can show videos o each demon-sraion.

www.middleschoolchemisry.com/mulimedia/chaper1/lesson5#air_has_mass_ballwww.middleschoolchemisry.com/mulimedia/chaper1/lesson5#air_has_mass_can

Maerials or he demonsraionBaskeball, very defaedBalance ha measures in gramsPumpCan o compressed gas (available a any oce supply sore)



Procedure

A. BaskeballPlace he defaed ball on he balance o ge he iniial.mass.

Ask sudens i hey hink he ball. will weigh more or less aer youpump air ino i.

Pump as much air ino he bas-.keball as you can and hen pu i

back on he balance.

B. Can o compressed gasPlace a can o compressed gas on.

a scale and check is mass.Ask sudens wheher i will weigh5.more, less, or he same i yousqueeze he rigger and le somegas ou.

Shoo gas ou o he can or a ew6.seconds and hen place he can

back on he scale.

Expeced resulsTe baskeball should weigh grams more han when i was defaed. Te can will

weigh a ew grams less han i did iniially.

3. sw imi mu .

Show he molecular model animaionParicles o a Gas.www.middleschoolchemisry.com/mulimedia/chaper1/lesson5#paricles_o_a_gas

Explain o sudens ha he molecules o a gas have very litle atrac-ion or one anoher and barely inerac wih each oher. Tey juscollide and bounce o. I may be hard or sudens o accep, bu inhe space beween he gas molecules here is nohing.



Noe:An inquisiive suden migh ask: I gas molecules aren atraced o each oher and canjus oa around, why don hey all jus oa away? Ta is a very good quesion. In ac veryligh gases like hydrogen and helium have oaed away and here are very litle o hese gasesin our amosphere. Dieren heavier gases, such as nirogen, oxygen, waer vapor, and carbondioxide, surround he Earh. In he big picure, graviy holds hese gases near he Earh as ouramosphere.


Sudens will answer quesions abou he demonsraion on he aciviyshee. TeExplain I wih Aoms & Molecules and ake I Furhersec-ions o he aciviy shee will eiher be compleed as a class, in groups,or individually depending on your insrucions. Look a he eacher ver-sion o he aciviy shee o nd he quesions and answers.

explore

4. hv u ivi f u w i i .

Quesion o invesigaeHow does heaing and cooling aec a gas?

Maerials or each group clear plasic cups8-oz plasic botleDeergen soluion in a cupHo waer (abou 50 C)Cold waer

eacher preparaionMake he deergen soluion or he enire class by adding easpoons o dishwashing liquid and easpoons o sugar o cup o waer. Genly sir unil he deergen and sugar aredissolved. Place abou ablespoon o deergen soluion in a

wide clear plasic cup or each group.

Procedure

A. Warming he air inside he botlePour ho waer ino an empy cup unil i is abou.-ull.

urn he botle over and dip he opening o he.botle ino he deergen o ge a lm o deergencovering he rim.



While holding he botle, slowly push he botom o he botle down ino he ho.waer.

Ask sudens:Wha can you do o make he bubble go down?

I sudens have rouble hinking o an answer, remind hem ha heaing he gasincreased he speed o he molecules, which made he bubble grow. Sudens shouldsugges ha hey should cool he gas in he botle. Tis can be done by puting he

base o he botle ino cold waer.

B. Cooling he air inside he botlePour cold waer ino anoher cup unil i is abou -ull..

I here is sill a bubble on he botle, slowly push he bo-5.om o he botle down ino he cold waer.

I a bubble is no sill on he botle, make anoher bubble by6. dipping he opening ino deergen and hen pushing hebotom o he botle ino ho waer again.

While holding he botle, slowly push he botom o he7.botle down ino he cold waer.

Expeced resulsWhen he botle is placed in ho waer, a bubble orms a he op o he botle. When hebotle is placed in cold waer, he bubble ges smaller. I may acually be pushed down ino

he botle.

5. r iu u bvi.


Wha happened o he lm o deergen soluion when you placed he botle inho waer?I ormed a bubble.

Wha happened o he bubble when you placed he botle in cold waer? I shrunk and wen ino he botle.

ell sudens ha you will show hem an animaion o help explain wha caused hebub-ble o grow and shrink when he air in he botle was heaed and cooled.



explaIn

6. sw imi bubb i i .

Show he animaionHeaing and Cooling Gas in a Botle.www.middleschoolchemisry.com/mulimedia/chaper1/lesson5#heaing_cooling_gas_in_botle

ell sudens ha he red arrows in he animaion represen he ouside air pushing downon he bubble lm. Explain ha heaing he air inside he botle makes he moleculesmove aser. Tese aser-moving molecules hi he inside o he botle and he bubble lmharder and more requenly. Tese molecules push agains he inside o he bubble lmharder han he surrounding air pushes rom he ouside. Tis pushes he bubble lm upand ou, orming a bubble.

Cooling he gas makes he molecules move more slowly. Tese slower-moving moleculeshi he inside o he botle and he bubble lm less oen and wih less orce. Te mole-

cules in he surrounding air are moving aser and push agains he bubble rom he ou-side. Since hese ouside molecules are pushing harder, he bubble ges pushed down andges smaller.

7. hv u w qui bu wi iki bubb ivi .

Give sudens ime o complee he ollowing quesions. Tey shouldreer o he drawing included on he nex page and on he aciviy shee.Once hey have answered he quesions, discuss heir explanaions as a whole group.

Wha caused he bubble o orm when you placed he botle in ho waer? Besure o wrie abou he speed o he molecules inside he botle and he pressurerom he ouside air.Poin ou ha he molecules o air inside he botlemove aser when hey are heaed and push harderagains he ouside air. Tis makes he bubble orm.

Why did he bubble ge smaller when you placedhe botle in cold waer? Be sure o wrie abou he

speed o he molecules inside he botle and hepressure rom he ouside air.

When he air inside he botle is cooled, he mole-cules move slower and do no push as hard agains heouside air. Te ouside air pushes agains he bubble,making i go down.

Read more aboutthe contraction andexpansion o gasesin the additionalteacher background

section at the end othis lesson.



hv u m mu i i, iqui, .8.

Show he molecular model animaion Comparing Solids,Liquids, and Gases.

www.middleschoolchemisry.com/mulimedia/chaper1/lesson5#comparing_solids_liquids_and_gasesBe sure sudens realize ha he molecules shown are rom hreedieren subsances all a room-emperaure. Te solid is no meling o become a liquidand he liquid is no evaporaing o become a gas. Te model is no rying o show saechanges bu insead show hree dieren subsances (such as meal, waer, and air), whichare solid, liquid, and gas a room-emperaure.

Explain he ollowing dierences o sudens:

Solid

Paricles (aoms or molecules) are very atraced o one anoher. Teyvibrae bu do no move pas one anoher. Te aoms or molecules say in xedposiions because o heir srong atracions or one anoher. A solid has a denie

volume and a denie shape.Liquid Paricles (aoms or molecules) are atraced o one anoher. Tey vibrae

bu are also able o move pas one anoher. A liquid has a denie volume bu doesno have a denie shape.Gas Paricles (aoms or molecules) are no atraced o each oher much a all andmove reely. A gas does no have a denie shape or volume. Te aoms or moleculeso a gas will spread ou evenly o ll any conainer.

You could use he ollowing example o help sudens appreciae how ar apar he mol-ecules o a gas are compared o he molecules in a liquid or solid:

Te molecules ha make up a gas are abou 00 o 000 imes urher apar hanhe molecules o a solid or liquid. Imagine wha a ablespoon o waer looks like. Iha same number o molecules was a gas, hey would be spread ou enough o llup a whole beach ball. A room-emperaure hey are moving a abou 000 milesper hour, bu over very shor disances.



Draw or projec he illusraionSolid, Liquid, and Gas.www.middleschoolchemisry.com/mulimedia/chaper1/lesson5#solid_liquid_and_gas

Have sudens use he projeced illusraion as a reerence as hey draw a model o solids,liquids, and gases on heir aciviy shee. Poin ou ha he number o moion lines is hesame or he solid, he liquid, and he gas. Tis indicaes ha he dieren subsances area he same emperaure. Have sudens wrie capions like hose lised below o describehe molecules in solids, liquids, and gases.

extendhv u w v i w b w9.w i i .

ell sudens o consider he ollowing scenario:

Imagine ha you work a a pary sore during he summer. You are going o ride homewih he owner o he sore whose car has been siting in he ho sun all day long. Teowner ells you ha you can ake home a big bunch o balloons, bu advises you o no

blow he balloons up all o he way. Knowing wha you do abou heaing he molecules oa gas, explain why he owners advice is wise.

You may choose o show he animaion Heaing Molecules o a Gas i you would like o givesudens a hin.

www.middleschoolchemisry.com/chaper1/lesson5/#heaing_and_cooling_gas

Atracions srong

enough o keep aoms in

orderly arrangemen

Vibrae in fxed posiions

Defnie volume and

shape

Atracions keep par-

icles ogeher bu hey

can slide pas each oher

Random arrangemen

Defnie volume, no

defnie shape

Atracions oo weak o keep

paricles ogeher

Paricles move independenly

No defnie volume or shape



Activity Sheet Name _______________________Chapter 1, Lesson 5Air, Its Really There Date ________________________

demonstrAtionbAsketbAll And compressed GAs

The demonstrations with the basketball and the can o compressed air were meantto show something about gases and matter. Matter is any-thing that has mass and takes up space.

Think about the demonstration with the defated and1.infated basketball. The basketball weighed moreater it was infated with air than when it was defat-ed. How does this show that gas is matter?

Think about the demonstration with the can o com-2.pressed gas. The can weighed less ater some gas wasshot out o the can. How does this show that gas ismatter?


You saw an animation o gas molecules inside a balloon.

What did you notice about the molecules o a gas:3.Do the molecules o a gas have strong or weak attractions?

Are the molecules o a gas randomly or orderly arranged?

When the molecules o a gas hit each other, do they normally sticktogether or bounce o?



Activity

Quesion o invesigaeHow do heaing and cooling aec a gas?

Maerials or each group clear plasic cups8-oz plasic botleDeergen soluion in cupHo waerCold waer

Procedure

A. Warming he air inside he botlePour ho waer ino an empy cup.unil i is abou -ull.

urn he botle over and dip he.opening o he botle ino hedeergen o ge a lm o deer-gen covering he rim.

While holding he botle, slowly.push he botom o he botle

down ino he ho waer.

B. Cooling he air inside he botlePour cold waer ino anoher cup unil i is abou -ull..

I here is sill a bubble on he botle, slowly push he botom5.o he botle down ino he cold waer.

I a bubble is no sill on he botle, make anoher bubble by6.dipping he opening ino deergen and hen pushing he bo-om o he botle ino ho waer again.

While holding he botle, slowly push he botom o he7.botle down ino he cold waer.




4. What happened to the lm o detergent solution when you placed the bottlein hot water?

5. What happened to the bubble when you placed the bottle in cold water?


You saw an animation showing the air molecules inside a bottle when it is placedin hot and cold water. Think o the animation and use the drawing below as a reer-ence to answer the questions at the top o the next page.

6. What caused the bubble to orm when you placed the bottle in hot water?

Be sure to write about the speed o the molecules inside the bubble and theorce on the bubble rom the outside air.



7. Why did the bubble get smaller when you placed the bottle in cold water?Be sure to write about the speed o the molecules inside the bubble and theorce on the bubble rom the outside air.

You saw an animation about the molecules in solids, liquids, and gases.

Draw circles to represent the molecules in a solid, liquid, and gas. Because all8.three dierent substances are all at the same temperature, draw the samenumber o motion lines near the circles or each substance. Under each box,write about the arrangement and motion o the molecules and the attrac-tions the molecules have or one another.

tAke it further

Imagine that you work at a party store during the summer. You are going to9.ride home with the owner o the store whose car has been sitting in the hotsun all day long. The owner tells you that you can take home a big bunch oballoons, but advises you to not blow the balloons up all o the way. Explainwhy the owners advice is wise. Be sure to discuss how heating aects themotion o the molecules in a gas.

Solid Liquid Gas



Chapter 1Student Reading

Chemistry is the study o matter

You could say that chemistry is the science that studies all the stu in the entire world. A morescientic term or stu is matter. So chemistry is the study o matter. Matter is all the physical

things in the universe. All the stars in the galaxies, the sun and planets in our solar system, theEarth, and everything on it and in it are matter.

All human-made objects, all organisms, the gases in the atmosphere, and anything else that hasmass and takes up space, including you, are examples o matter.

Chemistry is special because it looks at matter all the way down to its smallest parts: the atomsand molecules that matter is made o. To give you an idea about how small atoms and molecules

are, use a metric ruler to look at the length o one millimeter. It is about the size o a dash like thisone -. Try drawing a tiny line or dot that is about 1/10 as long as the dash. It might be about thesize o a period like the one at the end o this sentence. A hydrogen atom is about 1 ten milliontho the size o the period. So it would take about 10 million hydrogen atoms lined up next to eachother to go rom one side o the period to the other.

Here is another way to imagine how small atoms and molecules are. In about 1 tablespoon owater, there are about 600 billion trillion water molecules. Thats 600,000,000,000,000,000,000,000. This number is so huge that even i you could count one million molecules every second, itwould take you about 200 million centuries or about 20 billion years to count all the molecules ina tablespoon o water.

PHOTOS.COM PHOTOS.COM PHOTOS.COM



Studying chemistry can help make sense o many o the dierent things you see and do every day.What you eat and drink, the weather outside, the soap and water you wash with, and the clothesyou wear, are all a result o chemistry. The sports equipment you use, the materials your house ismade o, the way you get to school, and the electronic equipment you use are all a result o theinteractions o atoms and molecules.

Having a better idea o what atoms and molecules are and how they interact can help you betterunderstand the world around you.

Matter is made o atoms and molecules

We have already used the term atom and molecule a couple o times.You will learn a lot more about atoms and molecules in later chapters.For now, lets say that atoms and molecules are the extremely tiny

particles that make up all the matter on Earth. An atom is the basicbuilding block o all matter. A molecule is made o two or more atomsconnected or bonded together.

Even though atoms and molecules are not the same, the model we areusing in Chapter 1 shows both atoms and molecules as little circles orspheres. This model makes it easier to show some o the basic charac-teristics o the dierent states o matter on Earth.

MatterSolid, Liquid, Gas

On Earth, matter is either ound as a solid, liquid, or gas. Aparticular solid, liquid, or gas might be made up o individualatoms or molecules.

Here is a simplied model o three dierent substances. One isa solid, another is a liquid and the other is a gas

PHOTOS.COM PHOTOS.COM PHOTOS.COM PHOTOS.COM



In the picture, the little motion lines show that the particles (atoms or molecules) that make upthe solid, liquid, and gas are moving. In later chapters, the models o atoms and molecules will beshown with more detail.

As you look at these pictures, think about these two big ideas which are always true when talkingabout matter:

Matter (solid, liquid, and gas) is made up o tiny particles called atoms and molecules.The atoms or molecules that make up matter are always in motion.These rst two ideas make up a very important theory called the Kinetic-molecular theoryo matter.

Another big idea is that:The atoms or molecules that make up a solid, liquid or gas are attract-ed to one another.

In a solid, the atoms are very attracted to one another. Because o this

strong attraction, the atoms are held tightly together. The attractionsare strong enough that the atoms can only vibrate where they are.They cannot move past one another. This is why a solid keeps its shape.

In a liquid, the molecules are also in motion. The attractions betweenthe molecules in liquids are strong enough to keep the molecules close

to each other but not in xed positions. Although the molecules stayvery near one another, the attractions allow the molecules o a liquidto move past one another. This is why a liquid can easily change itsshape.

In a gas, the molecules are also moving. The attractions between the

molecules o a gas are too weak to bring the molecules together. Thisis why gas molecules barely interact with one another and are veryar apart compared to the molecules o liquids and solids. A gas willspread out evenly to ll any container.



When looking at the dierent states o matter, its kind o like a competition between the attrac-tions the molecules have or each other compared to the motion o their molecules. The attrac-tions tend to keep the atoms or molecules together while the motion tends to make the atoms ormolecules come apart.

cmi M

Solids Liquids Gases

Attractions Atoms or molecules arevery attracted to oneanother.

Atoms or molecules areattracted to one another.

Atoms or molecules arebarely attracted to oneanother.

Movement Vibrate but do not movepast one another.

Vibrate but are able tomove past one another.

Vibrate and move reelypast each other.

Volume and Shape Have a denite volumeand a denite shape.

Have a denite volume,but does not have a de-nite shape.

Does not have a denitevolume or a deniteshape.

Heating and cooling liquids

Heating and cooling a liquid can aect how ar apart or close together the molecules are.

One example is the red alcohol inside the thin tube o a thermometer. When the thermometeris heated, the molecules o alcohol move aster. This aster motion competes with the attractionbetween the molecules which causes them to spread out a little. They have no where else to goso they move up the tube.

When the thermometer is cooled, the molecules o alcohol slow down and the attractions bringthe molecules closer together. This attraction between the molecules brings the alcohol down inthe tube.



Heating and cooling solids

There is a device made out o a metal ball and ring that lets you see theeect o heating and cooling a solid. At room temperature, the balljust barely ts through the ring.

When the ball is heated suciently, it will not t through the ring.

This is because heating the metal ball increases the motion o itsatoms. This motion competes with the attractions between theatoms and makes the atoms move slightly urther apart. Theslightly larger ball no longer ts through the ring.

When the metal ball is cooled, the atoms slow down and theirattractions bring the atoms closer together. This allows themetal ball to t through the ring again.

Heating and cooling gases

The molecules o a gas are not very attracted to each other and are much urther apart than

in liquids and solids. This is why heating a gas easily increases themotion o the gas.

For example, i you dip the opening o a bottle in a detergent solu-tion and then heat the bottle, a bubble will orm on the bottle. Thishappens because heating the bottle increases the motion o the gasmolecules inside the bottle. Since molecules o the gas are not veryattracted to each other, they spread out quickly and easily. The mole-cules hit the inside o the bottle and the bubble lm harder and moreoten. The molecules push against the inside o the lm harder thanthe surrounding air pushes rom the outside. This pushes the bubble

lm out and orms a bubble.

I you cool the bottle while the bubble is still on top, the bubble willshrink and may go inside the bottle. This happens because coolingthe gas causes its molecules to slow down. These slower-moving mol-ecules hit the inside o the bubble lm less oten and with less orce.The molecules in the outside air are moving aster and push againstthe bubble rom the outside. Since the outside molecules are pushingharder, the bubble gets pushed down and in and gets smaller.



Additional Teacher BackgroundChapter 1, Lesson 5, p.49

Contracting and expanding happens dierently or a gas than it does or liquids and

solids.

Cooling a liquid or solidWhen a liquid or solid is cooled, he paricles (aoms or molecules) slow down. Te slowermoion allows he atracions beween he paricles o pull hemselves closer ogeher causing heliquid or solid o conrac.

Cooling a gasBu i works dierenly or gases. When a gas in a fexible conainer like a balloon or bubble iscooled, is aoms or molecules also slow down. Bu he atracions beween he paricles o a gas

are so weak ha hey canno pull hemselves closer ogeher like in a liquid or solid. Insead, heslower-moving molecules hi he inside o he balloon or bubble less requenly and wih lessorce. Tis resuls in a lower pressure inside he bubble han ouside. Te higher pressure on heouside pushes on he bubble, making i conrac.

Heating a liquid or solidWhen a liquid or solid is heaed, he paricles i is made o move aser. Tis increased moioncompees wih he atracions he paricles have or each oher causing hem o move slighlyurher apar.

Heating a gasWhen a gas is heaed, he paricles also move aser bu hey do no have o compee wih signi-can atracions. Te paricles hi he inside o he bubble more requenly and wih more orce.Tis resuls in a higher pressure inside he bubble han ouside. Te higher pressure on he insidepushes on he bubble, making i expand.



Chapter 2, Lesson 1: Heat, Temperature, and Conduction

Key ConceptsAdding energy (heaing) aoms and molecules increases heir moion, resuling in anincrease in emperaure.Removing energy (cooling) aoms and molecules decreases heir moion, resuling in a

decrease in emperaure.Energy can be added or removed rom a subsance hrough a process called conducion.In conducion, aser-moving molecules conac slower-moving molecules and ranserenergy o hem.During conducion he slower-moving molecules speed up and he aser-movingmolecules slow down.emperaure is a measure o he average kineic energy o he aoms or molecules o asubsance.Hea is he ranser o energy rom a subsance a a higher emperaure o a subsance

a a lower emperaure.Some maerials are beter conducors o hea han ohers.

SummarySudens will do an aciviy in which hea is ranserred rom ho waer o meal washers and henrom ho meal washers o waer. Sudens will view a molecular animaion o beter undersandhe process o conducion a he molecular level. Sudens will also draw heir own model o heprocess o conducion.

Objective

Sudens will be able o describe and draw a model, on he molecular level, showing how energyis ranserred rom one subsance o anoher hrough conducion.


SaetyMake sure you and your sudens wear properly ting goggles. Use cauion when handling ho

waer.

Materials or Each Group ses o large meal washers on a sringSyrooam cup lled wih ho waerRoom-emperaure waer hermomeersGraduaed cylinder or beaker

Materials or the Teacher Syrooam cupTermomeerHo plae or coee makerLarge beaker or coee po



Noe: Energy can also be ranserred hrough radiaion and convecion, bu his chaper only deals wihhea ranser hrough conducion.

engage

diu w w i i iqui ik u 1.

.Ask sudens:

Did you ever pu a meal spoon in ho soup or ho chocolae and hen ouchhe spoon o your mouh? Wha do you hink migh be happening, beween hemolecules in he soup and he aoms in he spoon, o make he spoon ge ho?Is no necessary or sudens o answer hese quesions compleely a his ime. I ismore imporan ha hey begin o hink ha somehing is going on a he molecularlevel ha causes one subsance o be able o make anoher hoter.


explore

hv u w w m-mu2.m i i w.

I you canno ge he maerials or all groups o do his aciviy, you can dohe aciviy as a demonsraion or show sudens he videos:www.middleschoolchemisry.com/mulimedia/chaper2/lesson1#heaing_washerswww.middleschoolchemisry.com/mulimedia/chaper2/lesson1#cooling_washers

Quesion o invesigae

Why does he emperaure o an objec change when i isplaced in ho waer?

Maerials or each group ses o large meal washers on a sringSyrooam cup lled wih ho waerRoom-emperaure waer hermomeersGraduaed cylinder or beaker



Maerials or he eacher Syrooam cupTermomeerHo plae or coee makerLarge beaker or coee po

eacher preparaionUse a sring o ie 5 or 6 meal washers ogeher as shown. Each group o sudens

will need wo ses o washers, each ied wih a sring.Hang one se o washers or each group in ho waer on a ho plae or in waer in acoee maker so ha he washers can ge ho. Tese washers will need o remain hounil he second hal o he aciviy.Te oher se should be le a room-emperaure and may be disribued o sudensalong wih he maerials or he aciviy.Immediaely beore he aciviy, pour abou 0 milliliers ( ablespoons) o ho

waer (abou 50 C) ino a Syrooam cup or each group. Be sure o pour one cup oho waer or you o use as a conrol.

ell sudens ha hey are going o see i he emperaure o ho waer changes as a resulo placing room-emperaure meal washers in he waer. Te only way o ell i he wash-ers cause he emperaure o change is o have a cup o ho waer wihou washers. Explainha you will have his cup o ho waer, which will be he conrol.

You will need o place your hermomeer in he cup o ho waer a he same ime he

sudens do. Have sudens record he iniial emperaure o he conrol in heir chars onhe aciviy shee, along wih he iniial emperaure o heir own cup o ho waer. Teemperaure o he wo samples should be abou he same.

ProcedurePlace a hermomeer in your cup o measure he.iniial emperaure o he waer. Record he em-peraure o he waer in he Beore column in hechar on he aciviy shee. Be sure o also record

he iniial emperaure o he waer in he conrolcup.

Use anoher hermomeer o measure he empera-.ure o he washers. Record his in he Beorecolumn.



Noe: I is a litle awkward o ake he emperaure o he washers wih a regular hermomeerbecause here is such a small poin o conac beween he bulb o he hermomeer and he sur-

ace o he washers. Te washers should be abou room-emperaure.

Ask sudens o make a predicion:

Wha will happen o he emperaure o he

waer and he washers i you place he wash-

ers ino he ho waer?

Wih he hermomeer sill in he waer, hold he.sring and lower he meal washers all he wayino he ho waer.

Observe any change in he emperaure o he.waer. Leave he washers in he waer unil he

emperaure sops changing. Record he em-peraure o he waer in each cup in he Aercolumn.

Remove he washers rom he waer. Ten ake and record he emperaure o he5.washers in he Aer column.

Empy he cup in a wase conainer or sink.6.

Expeced resulsTe emperaure o he waer will decrease a bi and he emperaure o he washers willincrease a bi. Te amouno emperaure decrease and increase is really no ha impor-an. Wha is imporan is ha here is a emperaure decrease in he waer and a empera-

ure increase in he washers.

Noe: Evenually wo objecs a dieren emperaures ha arein conac will come o he same emperaure. In he aciviy, hewashers and waer will mos likely be dieren emperaures. Forhe purposes o his aciviy, he washers and waer are only inconac or a shor ime, so mos likely will no come o he sameemperaure.

Read more aboutenergy and tempera-ture in the additionalteacher backgroundsection at the end othis lesson.

Room-emperaure washers placed in ho waer

emperaure o Beore Aer

Waer in your cup

Waer in he conrol cup

Meal washers



Sudens may ask why he emperaure o he waer wen down by a dieren amoun hanhe emperaure o he washers wen up. Te same amoun o energy le he waer as wenino he washers, bu i akes a dieren amoun o energy o change he emperaure odieren subsances.

3. hv u w w m i i m-mu w.

Ask sudens:How do you hink he emperaure will change i you place ho washers inoroom-emperaure waer?

Pour abou 0 milliliers o room-emperaure waer ino he conrol cup. Place a her-momeer in he cup and ell sudens he emperaure o he waer.

Pour abou 0 milliliers o room-emperaure waer ino your Syrooam cup..Place a hermomeer ino he

middle school chemistry

Documents