The proton number of barium is 56. It is in group 2 of the periodic table. How many electrons would you expect a barium atom to contain in its outer energy level?
It is an element of group -2 and it's electronic configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹° 4s² 4p⁶ 4d¹° 5s² 5p⁶ 6s². therefore it's outer most orbit is n = 6 , in which no. of the electrons are 2
