CHEMISTRY: THE STUDY OF STUFF

STRUCTURE OF THE ATOM

1) PROTONS and NEUTRONS are heavy and occupy the middle or NUCLEUS of the atom

2) ELECTRONS are extremely light and occupy the space around the nucleus within certain ENERGY LEVELS

3) The nucleus is extremely small compared to the total atom size, yet its mass makes up almost all the total mass

MASS LOCATION CHARGEPROTONSNEUTRONSELECTRONS

The Periodic Table arranged according to atomic numberATOMIC NUMBER

- equals # of PROTONSeg. Carbon (C) atomic number = 6number of protons = ______

- is the BIG number beside any element on a periodic table

ATOMIC MASS-gives the mass of the atom in AMU's

(AMU=Atomic Mass Unit)-equal to # of PROTONS + NEUTRONSeg. Beryllium (BE) has atomic mass = 9.01

this means Protons + Neutrons = 9(note: atomic mass is “weird” because it is the average of different isotopes with different weight)# neutrons = atomic mass - atomic number

other periodic table stuff-metals and nonmetal division-solid, liquid and gas-family

alkali, alkaline earth, chalcogens, halogens, noble gases

-period and family (groups)

Three main types of atoms1.elements: defined by the number of PROTONS2.ions: defined by the number of ELECTRONS3.isotopes: defined by the number of NEUTRONS

ELEMENTS electrically neutral. This means:

# of PROTONS = # of ELECTRONS

Eg’s

# protons #neutrons # electronsAlKHO

IONS elements that lose or gain some electrons because protons don't equal electrons anymore,

ions are CHARGED

SYMBOL: elementcharge

eg. Ca2+

If electrons leave, get a positive ion. If electrons are added, get a negative ion

trick: take the charge and subtract it from the atomic number to get the # of electrons

eg:

# protons #neutrons # electronsAl3+

Fe2+

H+

O2-

most elements WANT to be ions reason: they want FULL electron energy levels

(parking lots)**SEE PERIODIC TABLE FOR PATTERNS**

ISOTOPES are rare, special forms of elements have different atomic masses REASON: the addition or loss of NEUTRONS

(which makes it heavier or lighter)

Naming: “element name - atomic mass of isotope”eg : carbon-14, uranium-235, hydrogen-2, oxygen-18

#protons # neutrons # electronscarbon-14uranium-235hydrogen-2

8 10

Naming and Formulas

Elements BY THEMSELVES naming is easy...look at the table! writing a formula:

write the symbol with the state eg: Al(s)

Most elements BY THEMSELVES are monoatomic except for

diatomic: H2(g),N2(g),O2(g),F2(g),Cl2(g),Br2(l), I2(g), At2(g),

weird: P4(s), S8(s)

COMPOUNDS

Definition: pure substances made up of 2 or more different atoms bonded together in a specific ratio

Compounds form from the interaction of each atom's valence electrons

parking lot analogy2 types of compounds1) IONIC2) MOLECULAR

IONIC COMPOUNDS2 general names for ions

positive ions CATIONSeg.______,______,______

negative ions ANIONSeg.______,______,______

*IONIC compounds always involve a CATION joining an ANION

CATIONS are always found _________________________________

ANIONS are always found _________________________________

THEREFORE, IONIC COMPOUNDS ALWAYS INVOLVE A METAL JOINING A NONMETAL

*Metals want to give up their electrons to have full electron shells*Nonmetals want to "borrow" to fill their electron shellsWhen the metal lends out its electrons, it becomes POSITIVE

When the nonmetal borrows extra electrons, it becomes NEGATIVE

THE RESULT IS THAT THE POSITIVE METAL AND THE NEGATIVE NONMETAL "STICK" TOGETHER (LIKE 2 MAGNETS)

PROPERTIES OF IONIC COMPOUNDS-often form salts-often a change in energy (temperature or light)-often SOLID at room temperature-tend to dissolve in water, BUT NOT ALL DO!!!(check solubility table)

when ionic compounds dissolve, they split apart (DISSOCIATE) into their individual ions

water forms around them (sphere of hydration)

COMPLEX IONS (or polyatomic ions)

definition: a group of atoms bonded together that have an OVERALL positive or negative charge

**your periodic table containing ALL the complex ions you will work withEg. carbonate ion

thiosulphate ionacetate ionammonium ion

Notice that:-most have oxygen in them-most common suffix: "-ate"per _____ate 1 more oxygen_______ate most common_______ite 1 less oxygenhypo_____ite 2 less oxygenthio_______ replace an “O” with “S”

Task: Try to group the "Cl" ones together

Treat complex ions EXACTLY like single ions. Don't split up the team!!

NAMING IONIC COMPOUNDS

A) ionic FORMULA to NAMESTEPS:

1) The positive metal is named first2) The negative nonmetal is last and its ending is changed

"-ide" simple (usually)"-ate" complex"-ite" complex

eg. KICaCl2

NaNO3

Al2(SO4)3

Zn(NO3)2

changing NAME to IONIC FORMULA

IMPORTANT - you need to BALANCE the positive and negative sides so that the overall charge is

neutral

Use the CRISSCROSS method

Eg: sodium chloride

aluminum chloride

lithium carbonate

calcium phosphate

iron (III) chromate

MULTIVALENT Ionic compounds

-some metals (but NOT ALL) can have more than one charge -these are called MULTIVALENT ions

* Which one do you use when naming??

answer: Choose the metal "species" that, written AS IS, will balance the charge

HYDRATES of ionic compounds- a hydrate is any compound which tends to "pal around with" (loosely bind to) a specific number of water molecules

Eg: Copper (II) Sulfate pentahydrate-looks blue

FORMULA TO NAME- write the number of water molecules behind and space with a DOT ()

NAME TO FORMULA- write the compound name but put

"______hydrate" behind. Blank spot is a prefix that indicates number of water molecules

PREFIXES (**memorize**)mono =1 hexa =6di =2 hepta =7tri =3 octa =8tetra =4 nona =9penta =5 deca =10

eg:

MOLECULAR

ELEMENTS 3 Types of molecular elements1) Monoatomic - He, Ne, Ar, Kr (MOST)2) Diatomic - group VIIIA, O2, N2

3) OTHER (weird) - P4, S8

COMPOUNDS-held together by COVALENT BONDS-involves NONMETALS ONLY

Intramolecular Bonding differencesIonic bonds - DONATES to fill valence shellCovalent bonds - SHARES to fill valence

-very easy -use the PREFIX SYSTEM

RULES:1.1st element named normally2.2nd shortened to "-ide" ending3.PREFIXES (see above)used to indicate

number

Eg: carbon monoxidedinitrogen monoxidesulfur trioxide

PCl5

SF6

N2O4

...& you need to MEMORIZE these onesozone watermethane sucrosemethanol ammoniaethanol hydrogen peroxideglucose hydrogen sulfidepropane octane

ACID NAMINGacid: an aqueous hydrogen containing substance

2 ways to name:IUPAC: easy, makes sense, not commonCLASSICAL: weird, but commonly known

*we need to know BOTH

Classical NamingEg. hydrochloric acid and sulfuric acid

STEPS1) look at the ending of the IUPAC name

a) if "ide" "hydro____ic acid"b) if "ate" "______ic acid"c) if "ite" "______ous acid"

(ALCHEM tables have these rules on a little chart)

*Classical names USUALLY end with "acid"*Classical names don't always make sense:

Eg:aqueous hydrogen sulfate sulfuric acid aqueous hydrogen phosphate phosphoric acid

Chemical Reactions

Matter changes in one of 3 common ways:

physical change chemical change nuclear change

chemical reactions = changes to the arrangement of molecules

If the FORMULAS change, then it’s a CHEMICAL CHANGE

Empirical signs of chemical reaction color change temperature change (without outside influence) new odor state change (without outside influence)

eg: precipitate or gas formation

BALANCED EQUATIONS

The number of elements on one side HAVE TO EQUAL the number on the other!!!

Rules, Steps and Tricks before ANYTHING, make sure the formulas or

names are WRITTEN PROPERLY (including states)

you can ONLY change COEFFICIENTS to balance, NOT subscripts

Tip #1: BALANCE in the following order:1.anything except “O” or “H”2.then balance “H”3.then finally the “O”

Tip #2: If you have an odd number of a certain element, use the “odd-even” rule

Tip #3: If you notice that POLYATOMIC ions don’t change from reactants to products, balance them as if they were an element

Tip #4: ALWAYS DOUBLE CHECK at the end of your balancing. You should ALWAYS get balancing questions right!!

Types of Chemical Reactions

Now that you have balanced a few equations, you might notice some types of reactions:

There are 5 you need to know:1.FORMATION (OR COMPOSITION)

2.SIMPLE DECOMPOSITION

3.SINGLE REPLACEMENT

4.DOUBLE REPLACEMENT

5.COMBUSTION:

5a. HYDROCARBON COMBUSTION

6.ACID BASE:Predicting Reactions

Once you know the types of reactions, it’s actually pretty easy to figure out what might happen if given the reactant side:

Eg: Fe(s) + O2(g) ?

Only ONE thing CAN happen...a COMPOUND

Formation: ELEMENT + ELEMENT

Try to figure out a pattern for the rest of the types

Simple decomposition:

Single replacement:

Double replacement:

Combustion: