Question

How many electron with l=2 are there in an atom having atominj no 54?

Answer 1

electronic configuration of element with at.no=54 is

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6

for s l=o ,

for p l=1

for d l=2

.: 20 electrons are there