Question

find the valency of magnesium with atomic no 12

Answer 1

atomic no. is 12

so, no. of electron = 12

valency is the combining Capacity of an element..

OR

or outer most electron in the shell...

so write the electronic configuration of magnesium..

Element. Electronic configuration
-------------------------------------------------------------
Mg =). 2,8,2


so from electronic configuration we can see that outer most electron in magnesium is 2

therefore, valency = 2

Answer 2

Magnesium :

In this question we are asked to find the the valency of Magnesium (Mg)

We know that the atomic no: of Magnesium is 12.


Also ,
we know that the atomic no: is same as the no: of protons present .

Thus ,
no: of protons = 12

Also ,
no: of protons = no: of electrons

Therefore ,
no: of electrons = 12

Electronic configuration = 2 , 8 . 2

Valency is the combining capacity of an element.
The no: of electrons in its valence shell is 2.

Thus , the valency of Mg is 2.