Question

Why do $ 2d,1d, $ and $ 3f $ orbitals not exist?

Answer 1

Hint: The number that was written before the orbital can be known as principal quantum number. It was represented by $ n $ . It also corresponds to the energy level. First energy level consists of only s-orbital, second energy level consists of only s and p orbitals, third energy level consists of only s, p, and d-orbital.

Complete answer:
The region where there is a maximum probability of finding electrons is known as an orbital. There are different orbitals like s-orbital, p-orbital, d-orbital, and f-orbital.
The number of subshells in the first shell is one which is $ 1s $ and can accommodate only two electrons. The remaining sub-shells like $ 1p, $ and $ 1d $ can’t exist.
The number of subshells in the second shell are two, which are $ 2s $ and $ 2p $ can accommodate eight electrons. The remaining sub-shells $ 2d $ can’t exist.
The number of subshells in the third shell are three, which are $ 3s,3p, $ and $ 3d $ . These three sub-shells can accommodate eighteen electrons. the remaining sub-shells $ 3f $ does not exist.
The number of subshells in the fourth shell are four, which are $ 4s,4p,4d, $ and $ 4f $ . These four subshells can accommodate $ 32 $ electrons.
Thus, due to the energy of the shell and the number of electrons that are able to occupy each orbital. The orbitals like $ 2d,1d, $ and $ 3f $ orbitals do not exist.

Note:
Shell corresponds to the energy level. Each shell consists of a sub-shell. Orbital is present in the subshell. First shell corresponds to one sub-shell. Second shell corresponds to two sub-shells. Third shell corresponds to three sub-shells. Fourth shell corresponds to four sub-shells.