A neutral atom of an element has `2K,8L, 9M` and `2N` electrons .The atomic number of element is :
The total number of d electons are

Options

A. 1
B. 2
C. 3
D. 4

Explanation

To solve the question, we need to determine the atomic number of the element based on its electron configuration and find the total number of d electrons present.

### Step-by-Step Solution:

1. **Understanding Electron Configuration**:
- The given electron distribution is:
- 2 electrons in the K shell (n=1)
- 8 electrons in the L shell (n=2)
- 9 electrons in the M shell (n=3)
- 2 electrons in the N shell (n=4)

2. **Writing the Electron Configuration**:
- For the K shell (n=1):
- 2 electrons can be filled in the 1s orbital: **1s²**
- For the L shell (n=2):
- 2 electrons in the 2s orbital and 6 in the 2p orbital: **2s² 2p⁶**
- For the M shell (n=3):
- 2 electrons in the 3s orbital, 6 in the 3p orbital, and 1 in the 3d orbital: **3s² 3p⁶ 3d¹**
- For the N shell (n=4):
- 2 electrons in the 4s orbital: **4s²**

Therefore, the complete electron configuration is:
**1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹ 4s²**

3. **Calculating the Atomic Number**:
- The atomic number (Z) is equal to the total number of electrons in a neutral atom.
- Total electrons = 2 (from K) + 8 (from L) + 9 (from M) + 2 (from N)
- Total electrons = 2 + 8 + 9 + 2 = **21**
- Thus, the atomic number of the element is **21**.

4. **Finding the Total Number of d Electrons**:
- From the electron configuration, we see that there is **1 electron in the 3d subshell**.
- Therefore, the total number of d electrons is **1**.

### Final Answers:
- The atomic number of the element is **21**.
- The total number of d electrons is **1**.