The maximum number of electrons in an orbital, is governed by……..principle.

Options

A. Hund’s
B. Aufbau
C. Pauli’s
D. None of these

Explanation

To solve the question regarding the principle that governs the maximum number of electrons in an orbital, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the principle that determines the maximum number of electrons that can occupy a single orbital.

2. **Reviewing the Options**: The options provided are:
- A) Hund's Principle
- B) Aufbau Principle
- C) Pauli's Exclusion Principle
- D) None of these

3. **Analyzing Each Option**:
- **Option A: Hund's Principle**: This principle states that electrons will fill degenerate orbitals (orbitals of the same energy) singly first, with parallel spins, before pairing up. It does not specify the maximum number of electrons in a single orbital.
- **Option B: Aufbau Principle**: This principle describes the order in which electrons fill orbitals based on increasing energy levels. It does not address the maximum number of electrons in an orbital.
- **Option C: Pauli's Exclusion Principle**: This principle states that no two electrons in the same orbital can have identical sets of quantum numbers. Therefore, a maximum of two electrons can occupy an orbital, provided they have opposite spins.
- **Option D: None of these**: This option suggests that none of the principles apply, which is incorrect based on our analysis.

4. **Conclusion**: The principle that governs the maximum number of electrons in an orbital is the **Pauli's Exclusion Principle**. Therefore, the answer is **Option C**.

### Final Answer:
The maximum number of electrons in an orbital is governed by **Pauli's Exclusion Principle**.

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