Valence electron Electron gift withinside the valence shell of an atom is referred to as valence electron.
The valence shell is the outermost shell of an atom in its uncombined state, which includes the electrons maximum probably to account for the character of any reactions regarding the atom and of the bonding interactions it has with different atoms.
Outermost shell of Ni is the 4th shell i.e N shell. It includes 2 electrons. Therefore Ni has 2 valence electrons.
Final answer:-
Ni has two valence electrons.