Statement I ; Energy of 3d orbital < Energy of 4s orbital.Statement II ; Classical mechanics cannot explain the motion of electron.

(I) (n+l) value for 3d orbitals…..3+2=5 whereas for 4s orbital it is 4+0=4….Thus energy of 3d > 4s(II) Classical mechanics successfully explains motion of macro particles but fails to explain the motion of sub atomic particles;