Question

what is variable valency ? why it occurs​

Answer 1

Answer:

some elements combine with each other, sharing, donating or accepting electrons in different properties depending on its nature. example iron combines with oxygen to form iron oxide.

Answer 2

ʜᴏʟᴀ ᴍᴀᴛᴇ !

$\: \: \: \: \: \: \: \: \: \: \:$

⭐ᴀɴsᴡᴇʀ⭐

Certain elements have more than one valency. They exhibit variable valency. For example, copper, tin, iron and mercury exhibit variable valency. Copper combines with oxygen to form cuprous oxide (Cu2O) and cupric oxide (CuO).