1. Identify the Ions
* Calcium (Ca) is in group 2 of the periodic table, so it forms a +2 cation (Ca²⁺).
* Nitrogen (N) is in group 15, so it forms a -3 anion (N³⁻).
2. Balance the Charges
To create a neutral compound, the charges must balance. You need three calcium ions (3 x +2 = +6) and two nitride ions (2 x -3 = -6).
3. Write the Formula
The formula for calcium nitride is Ca₃N₂.
