The orbital diagram in which the Aufbau principle is violated

Options

A.
B.
C.
D.

Answer

To determine which orbital diagram violates the Aufbau principle, we need to understand what the Aufbau principle states. The Aufbau principle dictates that electrons fill atomic orbitals starting from the lowest energy level to the highest energy level.

### Step-by-Step Solution:

1. **Understanding the Aufbau Principle**:
- The Aufbau principle states that electrons will fill atomic orbitals in order of increasing energy levels. This means that the 1s orbital fills first, followed by 2s, then 2p, and so on.

2. **Analyzing the Given Options**:
- We need to look at the orbital diagrams provided in the options and check if they follow the Aufbau principle.

3. **Checking Option 1**:
- If the first option shows that the 1s orbital is filled before the 2s and 2p orbitals, then this option obeys the Aufbau principle.

4. **Checking Option 2**:
- In the second option, if we see that the 2p orbitals are filled before the 2s orbital, then this violates the Aufbau principle. According to the principle, the 2s orbital should be filled before any electrons occupy the 2p orbitals.

5. **Conclusion**:
- After analyzing both options, if option 2 shows that electrons are occupying 2p before 2s, then option 2 is the orbital diagram that violates the Aufbau principle.

### Final Answer:
The orbital diagram in which the Aufbau principle is violated is **Option 2**, where the 2p orbitals are filled before the 2s orbital.