The maximum number of electrons present in the $N$ shell is:

Explain the arrangement of orbitals in increasing order of energy on the basis of the $(n + l)$ rule.

Assertion :- In $H$-atom,the energy of $3d$-level is smaller than $4s$-level.
Reason :- In multi-electron species,an orbital with lower value of $(n+\ell)$ has energy smaller than the orbital with larger value of $(n+\ell)$.

The angular momentum of an electron depends on:

The maximum number of sub-levels, orbitals and electrons in $N$ shell of an atom are respectively

For azimuthal quantum number $l = 3$,the maximum number of electrons will be