Question

Valency atomic number and symbols of first 100 elements

Answer 1

valency depends on group
group 1 - valency 1
2 - 2
3-4
4-4
5-3
6-2
7-1
8-0

Atomic no. is the no. of protons. periodic table is arranged by it. So hydrogen has 1
helium 2
lithium 3
and so on.

Symbols you see in the picture.