(a) The resulting compound is an ionic compound since the elements of group 2 are metals and those of group 17, non-metals. When a metal reacts with a non-metal, electrons get transferred from the metallic atoms to the non-metallic atoms, and an ionic bond is formed.
(b) Yes, it will conduct electricity because an ionic compund has formed.
(c) Element X belongs to group 2 and its valency is 2. Element Y is from group 17 and its valency is 1. So, one atom of X combines with two atoms of Y to give a compound of the formula XY2.
(d) The valency of the element X is 2 because it belongs to group 2.
(e) Group 17 elements have seven valence electrons in their atoms.
Group number = valence electron+10
Valence electron = Group number - 10
= 17-10 = 7.