•Elements naturally exist in compounds

•2 or more chemically combined elements

•They form compounds to be more stable = have full outer energy levels of electrons

•8 for every element but H and He

•Two main types of bonds are ionic and covalent

•Ionic = between a metal and nonmetal.  The metal transfers electrons to the nonmetal.

•Covalent = between nonmetals.  Electrons are shared.

​Compound Review

​•An ionic compound is made of charged ions

•Cation = positively charged metal ion

•Positive because metals lose electrons

•Anion = negatively charged nonmetal ion

•Negative because nonmetals gain electrons

•Although an ionic compound is made up of charged ions, the overall charge of the compound must be zero

•Aka– the amount of (+) charge must equal the amount of (-) charge

Ionic Compounds

How to determine the Chemical Formula for an Ionic Compound

1. Write down the ions of each element with charge

2. Determine the # of each ion it takes to make a compound with no charge

        (aka, criss cross applesauce)

3. Write down the formula using subscripts to show how many of each ion it took

4. Reduce/simplify (if needed)

​Example:

Mg and P

Write the chemical formulas if the elements below formed a bond.

1. Lithium and Nitrogen

2. Magnesium and Iodine

3. Calcium and Oxygen

4. Sodium and Sulfur

Check your answers

How to Name Ionic Compounds
Formula ->Name

1.Write the name of the first element (the metal)

2.Write the name of the second element (the nonmetal) with an –ide ending

  Example: CaS

​Calcium sulfide