Answered

When an alkaline earth metal, M, reacts with oxygen the formula of the compound produced will be

AM₂O
BMO
CM₂O₃
DMO₂
EM₃O₄

Verified Answer :

D as the oxygen has gained to electrons from the magnesium in the reaction.

tadvisohil886

the answer is M2O

why?

the assumed valency of M should be 1+ ( because it reacts with oxygen and the valency is not provided)

the valency of oxygen is O2-

thus, by cris cross technique, we get M2O