An element X has a valency of 2. Write the simplest formula for:
(a) bromide of the element
(b) oxide of the element
(a) The valency of element X is 2 and that of bromine is -1. So according to the valencies of both the elements, the formula becomes XBr2.
(b) The valency of element X is 2 and that of oxide is -2. So according to the valencies of both the elements, the formula becomes XO.