why does variable valency of an element occur?

Asked by rashmibhattacharjee52 | 8th Apr, 2019, 11:03: PM

Expert Answer:

Sometimes, the same element may exhibit one valency in one compound and another valency in other compounds. This property is called as variable valency.

This occurs because of the different arrangement of the electrons in their outermost shell.

Example

Element

Symbol

         Valenciesexhibited          (variable valencies)

 ions

Copper

Cu

1, 2

Cu+1, Cu+2

Silver

Ag

1, 2

Ag+1, Ag+2

Gold

Au

1, 3

Au+1, Au+3

Iron

Fe

2, 3

Fe+2, Fe+3

Answered by Ramandeep | 9th Apr, 2019, 11:29: AM