POLYATOMIC COMPOUNDS

What are They?  groups of atoms (non-metals) that tend to stay together and carry an overall ionic charge.  involve combinations of metals with polyatomic ions  Example: Hydrogen ion (H 1+ ) combines with oxygen ion (O 2  ) to form a hydroxide ion (OH  ) which has an overall charge of 1 

Some Common Polyatomic Ions NameChemical Formula ammonium ionNH 4 + hydroxide ionOH  carbonateCO 3 2  nitrateNO 3  sulfateSO 4 2  hydrogen carbonatHCO 3  phosphatePO 4 3  *There is only one common polyatomic cation (ammonium ion NH 4 + )

Naming Polyatomic Compounds  Name the cation first (usually a metal or hydrogen)  Name the polyatomic ion second, as seen on your common ion sheet  When dealing with a transition metal use Roman Numerals to indicate the which charge is being used (same as binary ionic compounds). Ex: CaCO 3 H 2 SO 4 CuSO 4

Writing the Formulas for Polyatomic Compounds  Use the same method as binary ionic compounds (criss cross the charges)  Contain the polyatomic in brackets, never reduce the actual polyatomic ion Ex: Sodium Sulfate Magnesium Phosphate

Now You Try… Write the formula(s) and name the compound(s) which can be formed if we combine copper and carbonate.

Homework Complete the following on page 205 in your textbook: #1,2,3,4,5,6,8 Complete practice sheet (handout). MONDAY – QUIZ on all types of compounds