Answers

2016-02-12T13:21:07+05:30
Magnesium Mg
  atomic no = 12
  no of electrons=12
electronic configuration-
  k shell, l shell, m shell
  2, 8, 2
valency=2
2 5 2
2016-02-12T13:28:59+05:30
2,8,2 because the atomic no of mg is 12
1 5 1