Question

In which condition is variable valency possible

Answer 1

Answer:

Explanation:

The electrons present in the outermost shell of an atom are called valence electrons.

If the valency electrons are removed, the remainder is called Core.

In case of transition elements, the core is not stable.

So after the removal of valency electrons, one or more electrons can be lost from the outermost shell of the core also.

Hence these elements show two or more different valencies i.e. they have variable valency.

Example: Iron has two valencies Fe+2 and Fe+3

Answer 2

Explanation:

metals show variable valency. bcoz the presence of d orbital which shield the nuclear attraction on valency shell electrons. so the valency electrons ( more than one ) in the last shell tend to move out.