Write the atomic number of the element in the third period and group 1

1.	Write the atomic number of the element in the third period and group 17 of the period table.
Answer» Solution :In the third period third SHELL is filled and there are 8 elements (3S 3p). These will be two Ar(18). So element 11 and 12 are s BLOCK while 13 to 18 are p block belonging to groups 13 to 18. So the elment in the `17^th` GROUP must have an atomic number 17 (CHLORINE).

Discussion