An element-X has mass number 40 and contains 21 neutrons in its atom. To which group of the periodic table does it belong?

Q. An element-X has mass number 40 and contains 21 neutrons in its atom. To which group of the periodic table does it belong?

A.            Group 1

B.            Group 4

C.            Group 2

D.            Group 3

Answer: Group 4