Question

An element X forms a compound XH 3 with hydrogen. Another element Y forms a compound YX 2 with X. Given that the valency of hydrogen is 1, What are the valencies of X &Y?

Answer 1

X
`H_(3)`
H has a positive 1 charge. This means that having 3H = +3. This is a neutral compound so x= -3 because X+3H= 0

Y
`X_(2)` is also neutral so 2X+Y= 0
we know X=-3 So, 2(-3)+Y=0
-6+y=0
Y=+6 charge


Answer: The valency of X is -3. The valency of Y is 6