Comprehension # 1
Read the following rules and answer the questions at the end of it.
Electrons in various suborbits of an filled in increasing order to their energies.
Pairing of electrons in various orbitals of a suborbit takes places only after each orbital is half-filled.
No two electrons in an atom can have the same set of quantum number.
The sub-shell that arises after f sub-shell is called g sub-shell.

Options

A. it contains 18 electrons and 9 orbitals
B. it corresponds to `l=4` and first occurs in `5th` energy level
C. a g-orbital can have maximum of two electrons
D. all the above statements are true.

Explanation

To solve the comprehension question regarding the properties of the g subshell, we will analyze the statements provided and validate them step by step.

### Step-by-Step Solution:

1. **Understanding the g subshell**:
- The g subshell is the next subshell after the f subshell in the order of filling of atomic orbitals.

2. **Determining the number of orbitals in the g subshell**:
- The number of orbitals in a subshell can be determined using the formula:
\[ \text{Number of orbitals} = 2l + 1 \]
- For the g subshell, the azimuthal quantum number \( l \) is 4 (since g corresponds to \( l = 4 \)).
- Substituting \( l = 4 \) into the formula gives:
\[ \text{Number of orbitals} = 2(4) + 1 = 8 + 1 = 9 \]

3. **Calculating the maximum number of electrons in the g subshell**:
- Each orbital can hold a maximum of 2 electrons.
- Therefore, the maximum number of electrons in the g subshell is:
\[ \text{Maximum electrons} = \text{Number of orbitals} \times 2 = 9 \times 2 = 18 \]

4. **Verifying the energy level of the g subshell**:
- The g subshell first appears in the 5th principal energy level (n = 5). This is consistent with the filling order of orbitals.

5. **Applying Pauli's Exclusion Principle**:
- According to Pauli's Exclusion Principle, no two electrons in an atom can have the same set of quantum numbers. This principle applies to all subshells, including the g subshell.

### Conclusion:
- All statements regarding the g subshell are true:
1. The g subshell contains 18 electrons and 9 orbitals.
2. It corresponds to \( l = 4 \) and first occurs in the 5th energy level.
3. Each orbital in the g subshell can hold a maximum of 2 electrons.
4. Therefore, the correct answer is that all the above statements are true.