Nickel atom can lose two electrons to form `Ni^(2+)` ion. The atomic number of nickel is 28. From w hich orb ital will nickel lose two electrons.

Explanation

`_(28)Ni = ls^(2) , 2s^(2) , 2p^(6) , 3s^(2) , 3p^(6) , 3d^(8) , 4s^(2)` , Nickel lose 2 electrons from 4s (outerm ost shell) to form `Ni^(2+)` ion. So, `28 Ni^(2+) = Is^(2) , 2s^(2) , 2p^(8) , 3s^(2) , 3p^(6) , 3d^(8) , 4s^(@)`