1. Ion Formation
When an atom gains or loses electrons they become electrically charged particles called Ions
Metals tend to lose electrons
Positive ions are called CATIONS
Non-metals tend to gain electrons
Negative ions are called Anions

2. Ions of an Element Calcium Ion (cation), Ca2+ Atomic # 20 # of Protons
Neutral Calcium Atom have 20 protons = 20 electrons p+ p+ p+ e- e- e- 2+ p+ p+ p+ e- e- e- p+ p+ p+ e- e- e- p+ p+ p+ e- e- e-
Atomic #
# of Protons
# of Electrons 20 e- e- e- e- p+ p+ p+ p+ 20 18 p+ p+ p+ p+ e- e- e- e-
2+ means the overall charge is 2+
Lose 2 electrons

3. Ions of Elements Oxygen anion, O2- Zinc cation, Zn2+ Lithium ion, Li+8 30 3 16 65 7 8 30 3 8 35 4 10 28 2