An element which can exhibit valencies of 2, 4, and 6 can be :
(a) copper
(b) iron
(c) mercury
(d) sulphur

Q.

An element which can exhibit valencies of 2, 4 and 6 can be:

Q. Two elements X and Y have valencies of 5 and 3, and 3 and 2, respectively. The elements X and Y are most likely to be respectively :
(a) copper and sulphur
(b) sulphur and iron
(c) phosphorus and nitrogen
(d) nitrogen and iron

Q. Oxygen is divalent, but sulphur exhibits variable valency of $2,4$ and $6$ because:

Q. The atomic number of an element X is 8 and that of element Y is 4. Both these elements can exhibit a valency of :

(a) 1

(b) 2

(c) 3

(d) 4