1. Atoms with a charge

2. Ion: any atom that has a net electric charge; not neutral If the atom is not neutral, then there must be a different number of protons and electrons

3. First determine the number protons and electrons (either use the periodic table or it will be given to you) Figure out the difference between number of protons and electrons. If there are more electrons than protons, the charge is the negative difference If there are more protons than electrons, the charge is the positive difference

4. Once you figure this out, write the symbol of the element with the charge to the top right. For example: Lithium with 2 electrons is written as Li +1

5. Sodium 11 Protons +11 11 Electrons -11 Net charge 0 Sodium 11 Protons +11 (Loses e-)10 Electrons -10 Net charge +1 Positive ions lose electrons. Atoms can lose more than one electron (cations)

6. Chlorine Cl- 17 Protons +17 Gains e- 18 Electrons -18 Net charge -1 Negative ions gains electrons (anions)

7. An atom of oxygen has 10 electrons. What is its charge? An atom of Calcium has 18 electrons. What is its charge?