Arrange the following elements in increasing order of their atomic radii.

Li, Be, F, N

Name the element which is in :

(a) first group and third period

(b) seventeenth group and second period.

How do electronic configurations of elements change in second period of periodic table with increase in atomic numbers ?

Arrange the following elements in the in increasing order of their metallic character :

Mg, Ca, K, Ga

Rewrite the following statements after correction, if necessary :

(i) Elements in the same period have equal valency

(ii) The metallic character of elements in a period increases gradually on moving from left to right.