1. 9/1/11
As you come in… Turn in questions on page 50. Have out B.4 Cornell notes. Pick up 2 handouts.
Objectives
I can define an ion and the types of ions.
I can write the formula, name, and charges of ions of an ionic compound.
Catalyst
1. Convert using dimensional analysis.
867,530,912 centibarks to kilobarks
Identify the following as an element or compound.
2. CO 3. CaCl F Co

2. B.6 Chemical Symbols, Formulas, and Equations
An international “chemical language” is used to talk about atoms, elements, and compounds.
I. Chemical Symbols (Elements)
letters of the chemical language
either one or two letters
the first letter is always capitalized, the second is lowercase
Examples:
C (carbon)
Ca (calcium)
Pb (lead)
S (sulfur)
H (hydrogen)

3. II. Chemical Formulas (molecules)
words of the chemical language
chemical symbol indicates element
subscript below symbol indicates how many atoms of that element
if no subscript is listed, we assume just 1 atom
Examples:
H2O
C3H8
C6H12O6
NaCl

4. III. Chemical Equations (reactions)
sentences in the chemical language
summarizes the details of a chemical reaction
Chemical reaction: the breaking and forming of chemical bonds, causing atoms to be rearranged into new substances
the reactants (starting substances) are written on the left
the products (ending substances) are written on the right
an arrow is written in-between
All chemical equations must be balanced – the total number of each type of atom must be the same on both sides

5. B.9 Ions and Ionic Compounds
Ion – electrically charged atom (monatomic ion) or group of atoms (polyatomic ion) in which the number of electrons does not equal the number of protons
1. anion – negatively charged ion
Ex:
chloride Cl- (monatomic)
fluoride F- (monatomic)
sulfide S2- (monatomic)
nitrate NO3- (polyatomic)
hydroxide OH- (polyatomic)
phosphate PO43- (polyatomic)

6. 2. cation – positively charged ion Ex: sodium Na+ (monatomic) barium Ba2+ (monatomic) ammonium NH4+ (polyatomic)

7. B. Ionic Compound – substance that is composed of anions and cations and has no net electrical charge
Steps for writing formulas for ionic compounds
Look up (or remember) the charges for each ion.
Write the cation (+) first, then write the anion (-). Change monatomic anions suffixes to –ide.
Adjust subscripts on ions to make molecule neutral. (BURGERS AND BUNS!)
The correct formula will contain the fewest ions needed to make the total charge zero. (CaCl2 not Ca2Cl4)