IONIC FORMULAE AND NAMES Key wordsterms Polyatomic atoms

IONIC FORMULAE AND NAMES

Key words/terms • Polyatomic atoms • Carbonate • Nitrate • Sulfate • Hydroxide June 8, 2021 2

Introduction • We looked at forming ions last lesson and we can link this to both electronic structure and the periodic table 1+ 2+ June 8, 2021 3+ 3 - 2 - 1 - 3

Naming ionic compounds • Almost all ionic compounds have a two word name Cation Anion Ionic compound Sodium Chloride Sodium chloride Lithium Bromide Lithium bromide The ending of the anion is usually the part that changes, mostly to –ide. This tells us they contain only atoms from one element June 8, 2021 4

-ates and -ides • -ates • 2 - 3 3 June 8, 2021 5

Chemical formula • June 8, 2021 Compound name • • • Magnesium oxide Sodium chloride Lithium Bromide Calcium chloride Sodium hydroxide Copper sulfate Calcium carbonate Sodium nitrate Iron sulfide Copper carbonate 6

Writing chemical formula Anions Cations +1 +2 +3 -1 -2 3 3 22 - Ionic compounds in symbols are called chemical formula, these save time and give us the correct ratio of elements present. We need the charge of both anion and cation to write them June 8, 2021 7

Writing chemical formula • 22 - June 8, 2021 8

Alternative method – cross over 3 2 O Al 2 June 8, 2021 3 9