Question

find the valency of sodium and oxygen .(atomic number of sodium-11,atomic number of oxygen-8)​

Answer 1

Valency of Sodium is 1

Valency of Oxygen is 8-6= 2

Answer 2

Given details:

Atomic number of Sodium (Na) = 11

Atomic number of Oxygen (O) = 8

Solution:

Valency is the number of electrons in the outermost shell of the atom, that can be lose or gained in order to make the atom a stable one.

Configuration of Sodium (Na) is 1s2 2s2 2p6 3s1

So, there is one electron in the outer most shell.

If it loses one electron, it can become a stable one. (i.e.) 8 electrons in outer shell.

So, valency of Sodium is +1.

Configuration of Oxygen (O) is 1s2 2s2 2p4

So, there are 6 electrons in the outer most shell.

If it gains 2 electrons , it can become a stable one. (i.e.) 8 electrons in outer shell.

So, valency of Oxygen is -2.