Question

give reason :- when an element has more than one valency ​

Answer 1

Answer:

this is because the element looses electrons from it's penultimate shell.

Answer 2

Answer:

Normally, the metals donate electrons from their valence shell, so as to form positively charged ions. However, some metals lose electrons from the shell next to the valence shell. In such a situation the element exhibits more than one electropositive valency. Such elements are said to have variable valency.