Question

an element occupies group no .2 period no.3.this element heated in air to give a compound (A) find A and explain reaction

Answer 1

Element belongs to group no. 2 and period 3 is ◆Magnesium◆

Now comes to reaction-

magnesium reacts in two ways in air-
1◆Directly reacts with nitrogen as Lithium

=>Mg+N2-Mg3N2

2◆It reacts with oxygen to form monoxide

=>Mg+O2->MgO

hope it will help you!!

Balance urself!!