1. 2. In atom A how many electrons are there? Ion D? Ion E?
1. In atom A how many protons are there? Ion D? Ion E?
2. In atom A how many electrons are there? Ion D? Ion E?
3. How are the 3 diagrams the same?
4. How are they different?
5. One diagram is listed as an atom; the other two are listed as ions. What makes an ion different from an atom?
6. How does the atomic mass change when an atom becomes an ion?

2. Building on the Atom: Ions

3. Ion – an atom that has gained or lost electrons
Cation - positive charge
- Ion that has lost an electron (e-)
Anion - negative charge
- Ion that has gained an electron (e-)
# protons does not = # electrons

4. Ion – an atom that has gained or lost electrons

5. Atomic Symbol vs. Ion Symbol
Oxygen vs. Oxygen (-2) O
O-2
Sodium vs. Sodium (+1) Na
Na+
Zinc vs. Zinc (2+) Zn
Zn2+

6. Complete Small Stuff in the Small World Worksheet
Examples:
Atomic #
Atomic Mass p+ n0 e-
Phosphorous (-3) 15
30.974 16 18
Barium (+2) 56
137.33 81 54
Complete Small Stuff in the Small World Worksheet