Question

name of first 20 elements with their valency( full solve karke ki kaise valency find hoti hai)​

Answer 1

VALENCY OF FIRST 20 ELEMENTS WITH THEIR SYMBOL

Hydrogen [H] -valency- 1

Helium [He]-valency-0

Lithium [Li]-valency-1

Beryllium [Be]-valency-2

Boron [B]-valency-3

Carbon [C]-valency-4

Nitrogen [N]-valency-3

Oxygen [O]-valency-2

Fluorine [F]-valency-1

Neon [Ne] -valency-0

Sodium [Na]-valency-1

Magnesium [Mg]-valency-2

Aluminium [Al]-valency-3

Silicon [Si]-valency-4

Phosphorus [P]-valency-3

Sulphur [S]-valency-2

Chlorine [Cl]-valency-1

Argon [Ar]-valency-0

Potassium [K]-valency-1

Calcium[ Ca]-valency-2

The number of valence electrons can be determined if you look at group number. group number → units digit → valence electrons.