Question

Give the electronic configuration of Magnesium and Phosphorus.

Also , derive their valencies

Answer 1

Hello Deepu,

Magnesium :

Atomic number: 12
Electronic configuration :2,8,2
Valency: 2 as it loses 2 electrons to become stable.

Phosphorous:
Atomic number: 15
Electronic configuration: 2,8,5
Valency: 3  as it gains 3 electrons to become stable.

hope it helps u.....

Answer 2

Magnesium atomic number is 12
Electronic configuration 2,8,2
valancies is 2, that are belong second group and third period

Phosphorus atomic number is 15
Electronic configuration 2 ,8,5
Valancies is 3,that are belong fifteen group and third period

Very simple trick know the group and period of element
only we know atomic number element