JEE Chemistry 2025 Question with Solution

Given: Two statements about the number of orbitals in a shell and the spatial orientation of orbitals in a subshell.

Find: Which statement(s) are true.

For Statement (I), for a shell having principal quantum number $n$, the total number of orbitals is

$$n^2$$

So Statement (I) is true.

For Statement (II), for a subshell with azimuthal quantum number $l$, the magnetic quantum number $m_l$ gives the spatial orientation of orbitals and can take values from $-l$ to $+l$ including zero.

$$m_l = -l, \ldots, 0, \ldots, +l$$

So Statement (II) is also true.

Therefore, both statements are correct. The correct option is C.

Given:

• Statement (I): For a given shell, the total number of allowed orbitals is $n^2$.
• Statement (II): For any subshell, the spatial orientation of the orbitals is given by values from $-l$ to $+l$ including zero.

Find: The correct option.

Analyze each statement individually.

1. Statement (I): For a shell with principal quantum number $n$, the total number of orbitals is determined by the sum of orbitals present in all allowed subshells of that shell. This total is

$$n^2$$

Hence, Statement (I) is true.

2. Statement (II): For a given subshell, the azimuthal quantum number is $l$. The magnetic quantum number $m_l$ determines the spatial orientation of orbitals. Its allowed integer values are

$$-l \, \text{to} \, +l$$

including $0$. Thus Statement (II) is true.

Since both statements are true, the correct option is C.