An element has the electronic configuration 1s2,2s2 2p6,3s2 3p2. Its valency electrons are
6
2
3
4
An element has the electronic configuration 1s2,2s2 2p6,3s2 3p2 , (Si) . It's valency electrons are four.
An element having electronic configuration 1s2, 2s2 2p6, 3s2 3p6, 4s1 forms