1. Notes – Basic Chemical Nomenclature

2. Chemical Formulas A chemical formula is a way of expressing information about the atoms that make up a particular chemical compound.

3. Chemical Compounds A chemical compound is a substance consisting of two or more different elements chemically bonded together in a fixed proportion. Chemical compounds can be molecular or ionic.

4. Molecular compounds are composed of molecules  Single unit - molecule are made by combining a Nonmetal + Nonmetal

5. Ionic compound are composed of ions  Single unit – formula unit (whole number ratio) are made by combining a Metal (cation) + Nonmetal (anion) and yield a neutral compound

6. Other possibilities (not molecular or ionic) The combination of a Metal + Metal do not form compounds (They form alloys)  Sterling silver (silver and copper)  Bronze (tin and copper)  Steel (iron and carbon)  Brass (copper and zinc)

7. Type 1 - Ionic Ionic compounds that contain a metal and nonmetal Metal forms one cation (from group 1, 2, 13) the nonmetal forms the anion Write the Cation first and the anion second, put an “-ide” on the end of the nonmetal Example: NaCl – sodium chloride

8. Type 1 Examples Example: Al 2 O 3  Aluminum oxide Example: calcium chloride  CaCl 2

9. Type 2 - Molecular Compounds that contain only nonmetals 1 st element is named first using the full name 2 nd element is named as anion with the ending changed (- ide) Add a prefix to denote the number of atoms present  Prefix mono- is never used for naming the first element (carbon monoxide, not monocarbon monoxide)  Avoid awkward pronunciations – drop the final O or A of a prefix when the second element is oxygen (carbon monoxide not carbon monooxide)

10. Prefixes for Molecular compounds mono1hexa6 di2hepta7 tri3octa8 tetra4nona9 penta5deca10

11. Type 2 Examples Cl 2 O 6 – dichlorine hexoxide PBr 3 – phosphorous tribromide CCl 4 – carbon tetrachloride Dinitrogen tetrahydride – N 2 H 4 Nitrogen heptoxide – NO 7 Nitrogen monoxide – NO  Some compounds are referred to by common names (water is H 2 O, ammonia is NH 3 )