The atomic numbers of elements A, B, C, D and E are given below :

From the above table, answer the following questions -
(a) Which two elements are chemically similar ? (b) Which is an inert gas ?
(c) Which element belongs to `3^(rd)` period of periodic table ? (d) Which element among these is a non-metal ?

Explanation

The electronic configuration of the elements are as follows :

(a) Elements C and D are chemically similar since they have same number of valence electrons.
(b) Element B is an inert gas element since it has complete octet.
(c) Element C belongs to third period since it has three shells.
(d) Element A is a non-metal since it has five valence electrons.