Question

The shape of the orbital is given by:
A) Spin quantum number.
B) Magnetic quantum number.
C) Azimuthal quantum number.
D) Principal quantum number.

Answer 1

Hint:We know Pauli’s Exclusion principle:
The Pauli’s Exclusion principle states that in an atom or molecule no two electrons can have the same four quantum numbers. The condition at which the second electron can enter an orbital is if the spin of that electron is in opposite of the electron which is already present in the orbit.

Complete step by step answer:
As we know that the principal energy level of an electron refers to the orbital in which the electron is located relative to the atom’s nucleus.
Therefore, the option D is incorrect.
The Azimuthal quantum number denotes the subshell (orbital) to which the electron belongs and also determines the shape of the orbital and the energy associated with the angular momentum of the electron. Therefore the option C is incorrect.
The magnetic quantum number determines the preferred orientations of orbitals in space.
The spin quantum number’ is related to electron spin.
Therefore, the correct option is A.

Additional note: We must remember that the s sublevel has only one orbital, so maximum two electrons can be present. The p sublevel has three orbitals, so maximum six electrons can be present. The d sublevel has five orbitals, so maximum 10 electrons can be present. And the four sublevels have seven orbitals, and they can hold maximum 14 electrons.

Note:
We also know that the shape of an atomic orbital is determined by the angular momentum quantum number which is also known as Azimuthal quantum number (angular wave function) designated by "l". The different shapes of orbitals are also given as,
\[l = 0\;s - orbital\]
$l = 1\;p - orbital$
$l = 2\;d - orbital$
$l = 3{\text{ }}f - orbital$