The atomic number of three elements are given below : Write the symbol of the element which belongs to (i) group 13, (ii) group 15, of the periodic table. State the period of the periodic table to which these elements belong. Give reason for your answer.

The atomic number of three elements are given below : Write the sym

1.	The atomic number of three elements are given below : Write the symbol of the element which belongs to (i) group 13, (ii) group 15, of the periodic table. State the period of the periodic table to which these elements belong. Give reason for your answer.
Answer» Solution :Electronic configuration of the elements A, B and C are as given : (i) Element A belongs to group 13 (Group No. = 10 + 3 = 13). It is boron (B) (ii) Element B belongs to group 15 (Group No. = 10 + 5 = 15). It is nitrogen (N) Both these elements BELONG to SECOND PERIOD since they have TWO shells.