Title: Chem Review 3

PART 1 TOPIC: HISTORY OF PERIODIC TABLE

EQ: How was the first PT organized and how has it changed over the years?

Date

Title and

Highlight

Topic:

EQ:

NOTES: • Write out the notes from my website.

Use different types of note-taking methods to

help you recall info (different color

pens/highlighters, bullets, etc)

• When I lecture we will add more info, so

leave spaces in your notes

• DRAW ANY PICTURES, FIGURES, AND

WRITE OUT ANY PRACTICE

PROBLEMS/QUESTIONS.

• WE WILL ANSWER THEM TOGETHER.

So…LEAVE SPACES SO WE CAN

ANSWER QUES.

Summary (end of notes) :

1-2 Sentences of what you learned

Reflect

Question:

Reflect on

the

material by

asking a

question

(its not

suppose to

be

answered

from

notes)

The periodic table is the most important tool in the chemist’s toolbox!

Why is the Periodic Table important to me?

• You get to use it on every test.

• It organizes lots of information about all the known elements.

Dmitri Mendeleev: Father of the Periodic Table In 1869 he published a table of the elements.

1834 - 1907

A first look at the periodic table Dmitri Mendeleev organized all of the elements that were known at the time into rows and columns based on their chem/phy similarities and their masses.

Periodic Table •The table is called “periodic” because the pattern of similar properties repeats as you move from period to period.

Dmitri Mendeleev HOW HIS WORKED…

70 known elements.

Organized rows (periods) by increasing atomic weight.

Put elements in columns (groups) by their properties.

SOME PROBLEMS…

He left blank spaces for undiscovered elements. (Turned out he was right!)

He broke the pattern of increasing atomic weight.

Used his P.T. to predict the physical properties of three elements that were yet unknown.

Problems arose when new elements were discovered. Looking at our modern P.T., can you identify what problems might have caused chemists a headache?

Ar and K

Co and Ni

Te and I

Th and Pa

The fact that Mendeleev’s predictions for Sc, Ga, and Ge were amazingly close to the actual values, his table was generally accepted.

Henry Moseley

1887 - 1915

In 1913, through his work with X-rays, he determined the atomic number of the elements*……elements should be arranged in order of increasing atomic number is known as the periodic law.

Glenn T. Seaborg

After co-discovering 10 new elements, in 1944 he moved 28 elements out of the main body of the periodic table to their current location below the main part of the P.T. :Lanthanide and Actinide series.

1912 - 1999

Current Periodic Table:

How the P.T. has changed over time?

Current P.T.

Increasing ATOMIC NUMBER!!

Elements in the same group have similar chemical and physical properties!! (Mendeleev did

that on purpose.)

Past P.T.

• Increasing Mass number

(not any more!!!)

• Elements in the same group have similar chemical and physical properties!!

Still the same!!!

Title: Chem Review 3

PART 2 TOPIC: ORGANIZATION OF PT

EQ: How is the PT organized and why is it useful for us studying chemistry?

Students…. The next 6 slides are notes about the Periodic Table and how it is organized.

You can either make a sketch (please don’t draw every box) for each slide

OR

Make one BIG (entire page) Sketch and label all notes on that one sketch.

Your choice!

The horizontal rows of the periodic table are called PERIODS (7).

Make a Sketch

with notes

The vertical columns are called GROUPS (18), or FAMILIES.

The elements in any group have similar physical and chemical properties!

Make a Sketch

with notes

1A

2A 3A 4A 5A 6A 7A

8A

Elements in the 1A-8A groups are called the representative or main group elements

Make a Sketch

with notes

The group B are called the transition elements

Make a Sketch

this with notes

The elements in the periodic table can be broadly classified as metals,

nonmetals, and metalloids.

Types of Elements

Sketch this

with notes

3 classes of elements - METALS

Located to the _______ of the dark zig-zag line

All Solids!!! Except one – who is it??

shiny surface

Tend to be white/gray/silvery (common exceptions: copper and gold)

◦ ______________ (you can pound it into a flat sheet)

◦ ______________ (you can draw it into a thin wire)

◦good _______________ (heat/electricity)

◦Metals tend to LOSE electrons in chemical changes.

left

malleable

ductile

conductors

3 classes of elements - NONMETALS

Located to the ___________ of the dark zig-zag line.

◦_______ surface

◦ ______________

◦Some are solids and some are gases. Only 1 liquid.

◦good _______________ and poor conductors

◦Nonmetals tend to GAIN electrons in chemical changes.

◦Vary in color (P - red/white, S – yellow, C – black/clear, I – purple, Br – brownish red, etc)

right

dull

brittle

insulators

sulfur

Sketch this

with notes

3 classes of elements – METALLOIDS (only 8)

Located on the border of the dark zig-zag line.

◦ the dividing line between metals and nonmetals.

◦ All SOLIDS!

◦ Also called “semimetals”

◦ Behave (chemically) as nonmetals, but look physically & electrical conductivity resembles metals.

◦ Semiconductors – they do conduct some heat/electricity

◦ Used in computers, cell phones, and other modern gadgets.

silicon

Sketch this

with notes

Hydrogen

Hydrogen belongs to a family of its own.

Hydrogen is a nonmetal!!!

It’s a diatomic, reactive gas.

Facts

Hydrogen was involved in the explosion of the Hindenberg.

Hydrogen is promising as an alternative fuel source for automobiles

Group 1 - Alkali Metals (not H!!!)

•Very reactive metals (solids) with air

and water

•Never found pure in nature, too reactive

(always combined with something else in

nature like in salt).

•All have one valence e-

•Soft enough to cut with a butter knife

•Reactivity of these elements increases

down the group

Alkali Metal Family

Video Clip

Sketch this

with notes

Group 2 - Alkaline Earth Metals

•Reactive metals (solids) that are always

combined with nonmetals in nature.

•Not found pure in nature (too reactive but

less reactive than alkali metals)

• “Alkaline” means “basic”

•All have 2 valence e-

•Mg and Ca important for our body!!!

•Also, used in batteries

Sketch this

with notes

Groups 3-12: Transition Metals Sketch this

with notes

All solids except Mercury

Less reactive harder metals

Includes metals used in jewelry and construction.

Metals used “as metal.”

Transition Metals Groups 3-12

Group 14 - Carbon Family

4 Valence e-

Elements important to life and computers (Si and Ge).

Carbon is the basis for an entire branch of chemistry called ORGANIC Chem.

Sketch this

with notes

Group 15 - Nitrogen Family

5 valence e-

Nitrogen makes up over 80% of the atmosphere.

Nitrogen and phosphorus are both important in living things.

The red stuff on the tip of matches is phosphorus.

Sketch this

with notes

Group 16 - Oxygen Family or Chalcogens

6 valence e-

Oxygen is necessary for respiration.

Many things that stink, contain sulfur (rotten eggs, garlic, skunks,etc.)

Sketch this

with notes

Group 17 - Halogens

• 7 valence e-

• Very reactive, diatomic,

nonmetals

• Not found pure in nature

• Always combined with other

elements in nature .

• Used in some light fixtures

• Used as disinfectants and to

strengthen teeth.

Sketch this

with notes

Group 18 - Noble Gases • 8 valence e- (except He has 2 e-)

• VERY unreactive, monatomic gases

• Only elements found pure in nature

• Colorless, odorless, and unreactive;

• Don’t form compounds!!!

(These are also called “Inert gases”)

• Used in lighted “neon” signs and

balloons.

Sketch this

with notes

A

l

k

a

l

i

M

e

t

a

l

s

A

l

k

a

l

I

n

e

E

a

r

t

h

M

e

t

a

l

s

N

o

b

e

l

G

a

s

e

s

H

a

l

o

g

e

n

s

Transition Metals

Inner Transition Metals

Representative Elements

Transition Elements

Rep

resen

tativ

e E

lem

en

ts

METALS

Periods

Gro

up

s

Nonmetals

QUESTIONS

Title: Chem Review 3

PART 3 TOPIC: ISOTOPES

EQ: What part of the atom changes when you have isotopes of elements?

Atomic number (Z).

Protons determines the identity of the element.

A# = p+ = e- (atoms are

neutral)

The Mass Number (A),

(rounded to the nearest

integer)

Mass# = p+ + no

# of neutrons = mass # – p+

Isotopes: When the Number of Neutrons & Mass # Varies

All atoms of an element have the same # of protons.

Atoms with the same # of protons but different # of neutrons (this causes the mass # to also change) are called isotopes.

EXAMPLE OF AN ISOTOPE

Cl 35

17 Cl 37

17

20 NEUTRONS

ATOMIC MASS

18 NEUTRONS

ATOMIC NUMBER

So…

Atomic# = p+ = e-

(if atom is neutral) HOWEVER…..what if the atom is not neutral?

Electrons

•Electrons can be lost or gained = Chemical

Reaction, which make up more than 99% of

all rxns in life)

• When electrons are lost or gained, IONS are

formed.

•And electrons won’t equal protons no

more!!! Atomic# = p+ = e- •

Ions: Cations vs. Anions

Positive ions (lose e-) are called cations.

Negative ions (gain e-) are called anions.

The charge of an ion is shown in the upper right corner of the symbol.

Ion Symbol Notation

X Mass

number

Atomic

number Subscript →

Superscript → +2

Lost 2 e-

So… how do you know how many electrons atoms will lose or gain to form an ion?

Ions and the Periodic Table

The # associated with the A groups above each representative (main-group) column on the P.T. —1 through 8—gives the number of valence electrons (electrons on the far outside of the atom – these e- are the ones used first for chemical bonding!!!)

The key to predicting the charge acquired by an element is its position in the periodic table relative to the noble gases. Why noble gases?

Elements that form predictable ions

If an atom has a charge associate with it, it is an ION:

88 2

38 Sr

How many protons, neutrons, and electrons are there?

Important: If an atom has a negative charge = an anion. If an atom has a positive charge = a cation.

Practice Problem #1

Determine the number of protons, neutrons and electrons in this atom. Is this a cation or anion?

356

26 Fe

Practice Problem #2

Determine the number of protons, neutrons and electrons in this atom. Is this a cation or anion?

232

16

S

Practice Problem #3 How many protons, neutrons & electrons are there in the following?

a. Cl-38 d. 35Cl-1

b. Br-80 e. 32S-2

c. N-14 f. 56Fe+3