question_answer 59)

    Arrange the following elements in increasing order of their atomic radii. (a)               (b)

Answer:

                  (a) Atomic radii decrease along a period from left to right due to increasing nuclear charge. Li, Be F and N belong to same period. Thus, the atomic radii of Li, Be, F and N increase in the order: F < N < Be < Li. (b) Atomic radii increase in a group from top to bottom due to the corresponding increase in the number of filled electronic shells. Cl, At, Br, I belong to same group. Thus, atomic radii of Cl, At, Br and I increase in the order:.