Answer:
a) Valency of A=+5
b) Chemical formula of its chloride=ACl5
Step-by-step explanation:
(a) Let the valency of element A be x, then 2x + 5(-2) = 0
As oxegen has a valency of =-2 and overall the compound must be neutral
x=10/2
So, x = valency of element A = 5
(b)(b) As valency of element A is 5 and valency of chlorine is -1,
So, the formula of chloride of A is ACl5.