Question

Which atom has the electron configuration 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d²? and 1s²2s²2p⁶3s²3p⁶3d⁷4s²?

Answer 1

1 is correct as d sub shell cannot hold more than 6 electrons
Hope it helps : )