Ionic Compounds (p. 176 – 180, 203 – 211). Ionic Compounds. M ost of the rocks and minerals that make up Earth’s crust consist of positive and negative ions held together by ionic bonding. An ionic compound is composed of positive and negative ions that are
combined so that the numbers of positive and negative charges are equal.
collection of atoms from which an ionic compound’s formula can be
Common Ion Charges
Al 2 O 3
(6 +) + (6-) = 0
Formula is Al2O3
the ending of the polyatomic ion doesn’t change