Assertion: Energy of the orbitals increases as` 1s lt 2s = 2p lt 3s = 3p lt 3d lt 4s =4p =4d =4f lt `…… in a hydrogen atom.
Reason:Energy of the electron depends completely on principal quantum number.

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion
B. If both assertion and reason are true but reason is not the correct explanation of the assertion
C. If assertion is true but reason is false
D. If the assertion and reason both are false

Answer

C

Explanation

Assertion is true but reason is false. The order 1s lt 2s =2p lt 3s = 3p = 3d lt …. Is true for the energy of an electron in a hydrogen atom and is solely determined by Principal quantum number. For multielectron system energy also depends on azimuthal quantum number. The stability of an electron in a multi-electron atom is the net result of the attraction between the electron and the nucleus and the repulsion between the electron and the rest of the electron present . Energies of different subshell (azimuthal quantum number) present within the same principal shell are found to be in order of s lt p lt d lt f