The orbital diagram in which the Aufbau principle is violated is

Options

A.
B.
C.
D.

Explanation

To determine which orbital diagram violates the Aufbau principle, we need to analyze the options given in the question. The Aufbau principle states that electrons occupy the lowest energy orbitals first before moving to higher energy orbitals.

### Step-by-Step Solution:

1. **Understanding the Aufbau Principle**:
- The Aufbau principle dictates that electrons fill orbitals starting from the lowest energy level to the highest. For example, the 1s orbital fills before the 2s, and the 2s fills before the 2p.

2. **Analyzing the Options**:
- **Option A**: 2s is completely filled (2 electrons), and 2p has 2 electrons. This follows the Aufbau principle.
- **Option B**: 2s is completely filled (2 electrons), and 2p has 3 electrons distributed in three different orbitals. This also follows the Aufbau principle.
- **Option C**: 2s has only 1 electron, while 2p has 3 electrons. Here, the 2s orbital is not completely filled before electrons are placed in the 2p orbitals, which violates the Aufbau principle.
- **Option D**: 2s is completely filled (2 electrons), and 2p is also filled with 4 electrons. This follows the Aufbau principle.

3. **Identifying the Violation**:
- Since Option C has the 2s orbital with only 1 electron while the 2p orbital has 3 electrons, it violates the Aufbau principle because the 2s orbital should be completely filled before any electrons are placed in the 2p orbital.

4. **Conclusion**:
- Therefore, the correct answer is **Option C**, as it is the only option that violates the Aufbau principle.

### Final Answer:
**Option C** is the orbital diagram in which the Aufbau principle is violated.

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