Question

Which shape is associated with an orbital designated by n=2 and l=1?
(A) Spherical
(B) Tetrahedral
(C) Dumb-bell
(D) Pyramidal

Answer 1

Hint: The shape of an orbital is dependent on its azimuthal quantum number. The azimuthal quantum numbers for s-orbital is 0, for p-orbital is 1, etc.

Complete step by step solution:
Let’s see what the answer is:
The azimuthal quantum number is designated by l.
The azimuthal quantum number tells us about the shape of the subshell in which the electron is present.
In the above question l is 1, which means the subshell is p. The shape of p-subshell is dumb-bell.
The shape of the s-subshell is spherical. But for s-subshell l is 0. So, option (A) is incorrect.
The shape of $s{{p}^{3}}$ hybridization is tetrahedral. It is not the shape of any orbital. So, option (B) is also incorrect.
If a lone pair is present in $s{{p}^{3}}$ hybridization, the shape is no longer tetrahedral. It becomes pyramidal in shape. So, option (D) is also incorrect.
In option (C) dumb-bell shape is given. So, it is the correct answer.
Hence, the answer to the above question is option (C).

Additional Information:
The principal quantum number is denoted by ‘n’. It tells us about the shell in which the electron is present. It also tells us about the size of the atom. It also tells us about the energy of the shell.

Note: The azimuthal quantum number is also called orbital angular momentum quantum number. It gives us the angular moment of the orbital.