the orbital diagram in which aufbau principal is violated is :

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 indicates that electrons fill orbitals starting from the lowest energy level to the highest. Here’s a step-by-step solution to the question:

### Step-by-Step Solution:

1. **Understand the Aufbau Principle**:
- The Aufbau principle states that electrons occupy the lowest energy orbitals first before moving to higher energy orbitals.

2. **Identify the Energy Levels**:
- In general, the order of increasing energy for the orbitals is: 1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p, etc.

3. **Analyze Each Orbital Diagram**:
- Look at each orbital diagram provided in the question and determine the filling order of the electrons in the orbitals.

4. **Check for Violations**:
- If an orbital diagram shows that electrons are present in a higher energy orbital (like p) before the lower energy orbital (like s) is fully filled, it violates the Aufbau principle.

5. **Identify the Correct Diagram**:
- After analyzing the diagrams, we find that in the second diagram (option B), the s orbital is only half filled while electrons are present in the p orbitals. This indicates that the lower energy s orbital is not fully occupied before the higher energy p orbitals are filled, which violates the Aufbau principle.

6. **Conclusion**:
- Therefore, the orbital diagram in which the Aufbau principle is violated is option B.

### Final Answer:
The orbital diagram in which the Aufbau principle is violated is option B.