Question

Write the electronic configuration of the first 3 elements going down the group

Answer 1

Answer:

•hydrogen =1 ( atomic no)

valence electron = 1

• helium= 2 ( atomic no)

electronic configuration = 2

valence electron =2

•lithium = 3 ( atomic no)

electronic configuration=2,1

valence electron = 1

in the first three groups in the first shell (k) they have maximum 1 and 2 electrons and maximum times atomic no is the electronic configuration itself  and in the valence shell they in hydrogen there is no valence electrons.

Hope this will helpfull