An element M M\,M belongs to Group 2 of the Periodic Table, and an element A A\,A belongs to Group 15 (5).
What is the empirical formula of the stable ionic compound formed between M M\,M and AAA?
M2A5M_2A_5M2A5
M3A2M_3A_2M3A2
M2A3M_2A_3M2A3
MA2MA_2MA2