What is the atomic number of the element with the maximum number of unpaired 4p electron.

Options

A. 33
B. 26
C. 23
D. 15

Explanation

To determine the atomic number of the element with the maximum number of unpaired 4p electrons, we will analyze the electronic configurations of the given atomic numbers: 33, 26, 23, and 15.

### Step-by-Step Solution:

1. **Identify the Atomic Numbers and Their Corresponding Elements:**
- Atomic number 33 corresponds to Arsenic (As).
- Atomic number 26 corresponds to Iron (Fe).
- Atomic number 23 corresponds to Vanadium (V).
- Atomic number 15 corresponds to Phosphorus (P).

2. **Write the Electron Configurations:**
- For **33 (Arsenic)**:
- The electron configuration is:
\[ \text{[Ar]} \, 3d^{10} \, 4s^2 \, 4p^3 \]
- For **26 (Iron)**:
- The electron configuration is:
\[ \text{[Ar]} \, 3d^6 \, 4s^2 \, 4p^0 \]
- For **23 (Vanadium)**:
- The electron configuration is:
\[ \text{[Ar]} \, 3d^3 \, 4s^2 \, 4p^0 \]
- For **15 (Phosphorus)**:
- The electron configuration is:
\[ \text{[Ne]} \, 3s^2 \, 3p^3 \]

3. **Count the Unpaired Electrons in the 4p Orbital:**
- For **Arsenic (33)**:
- The 4p subshell has 3 electrons, which are unpaired.
- For **Iron (26)**:
- The 4p subshell has 0 electrons (all paired).
- For **Vanadium (23)**:
- The 4p subshell has 0 electrons (all paired).
- For **Phosphorus (15)**:
- The 4p subshell has 0 electrons (all paired).

4. **Determine the Maximum Number of Unpaired 4p Electrons:**
- The only element with unpaired electrons in the 4p subshell is Arsenic (33), which has 3 unpaired electrons.

5. **Conclusion:**
- Therefore, the atomic number of the element with the maximum number of unpaired 4p electrons is **33**.

### Final Answer:
The atomic number of the element with the maximum number of unpaired 4p electrons is **33**.