Question

An element occupies group number 1 and period number 2. This
element burns with air and forms compound A. With water, it gives
compound B, with hydrogen it forms an ionic compound C. Identify the
elements, A, B and C.

Answer 1

The element is Lithium(Li);
A=Li₂O(Lithium oxide);
B=LiOH(Lithium hydroxide);
C=LiH(Lithium hydride).
hope i helped u:).