Which pair represents elements belonging to the same group and shows increasing atomic radius from top to bottom?

Options

  • A. Li < Na < K
  • B. K < Na < Li
  • C. Li < Be < B
  • D. B < C < N
  • E. None of the above

Correct Answer (Detailed Explanation is Below)

A. Li < Na < K

Detailed Explanation

Li, Na and K belong to Group 1. Atomic radius increases down the group, giving Li < Na < K.