The electronic configurations of four elements are given in brackets:
$L(1s^2, 2s^2\ 2p^1);$ $M(1s^2, 2s^2\ 2p^5)$
$Q(1s^2, 2s^2\ 2p^6, 3s^1);$ $R(1s^2, 2s^2\ 2p^2)$
The element that would most readily form a diatomic molecule is:

• A
  $Q$
• B
  $M$
• C
  $R$
• D
  $L$