Answer:
to balance this equation, your going to put a 2 in front of the "Ca" then that makes the equation look like this "2Ca + N2 ⟶ Ca3 + N2" since the "Ca" had one atom, we added two more atoms
as we all know 1 + 2 = 3
then that gives us 3 "Ca's" on both sides
hoped this help and good luck on your test! :D
Explanation: