Here's why:
* Potassium (K) is in group 1 of the periodic table, meaning it has a +1 charge as a cation (K⁺).
* Nitrogen (N) is in group 15, meaning it has a -3 charge as an anion (N³⁻).
To achieve a neutral compound, you need three potassium ions (3 x +1 = +3) to balance the charge of one nitride ion (-3).
