Write the atomic number of the element present in the third period and seventeenth group of the periodic table.

Explanation

In the third period the filling up of only 3s- and 3p- orbitals . Therefore in this period there are only two s- and six p- block elements .since third period starts with Z= 11 and ends at Z= 18, therefore elements with Z= 11 and Z = 12 are s- block elements . The next six elements with Z= 13 to 18 are p- block elements and belong to groups 13, 14 , 15, 16, and 18. Therefore the element which will lie in the third period and seventeenth group will have Z= 10 + 7 = 17