An element with atomic number 20 will be placed in which period of the periodic table

Answer

2

Explanation

According to the electronic configuration `(1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 4s^(2))`, the last electron resides in ssubshell and has 2 electrons, thus the group number is 2