The screening effect of s, p, d and f subshells lies in the order

Options

A. `s gt p gt d gt f`
B. `s lt p lt d lt f`
C. `d gt p gt s gt f`
D. `s gt f gt d gt p`

Answer

To determine the order of the screening effect of s, p, d, and f subshells, we need to understand the concept of screening effect and how different subshells interact with the nucleus and valence electrons.

### Step-by-Step Solution:

1. **Understanding the Screening Effect**:
- The screening effect refers to the phenomenon where inner shell electrons reduce the effective nuclear charge felt by outer shell (valence) electrons. This occurs because the inner shell electrons repel the outer shell electrons, making them feel less attraction from the nucleus.

2. **Analyzing Subshells**:
- **s Subshell**: The s subshell is closest to the nucleus and has no inner electrons between it and the nucleus. Therefore, it experiences the maximum attraction from the nucleus and has the least screening effect.
- **p Subshell**: The p subshell is next in line. It is still relatively close to the nucleus but has some screening from the inner s electrons. Thus, it experiences a moderate level of attraction.
- **d Subshell**: The d subshell is further away from the nucleus and has more inner electrons (both s and p) that contribute to screening. Therefore, it experiences a lower effective nuclear charge compared to s and p.
- **f Subshell**: The f subshell is the farthest from the nucleus and has the most inner electrons (s, p, and d) contributing to screening. As a result, it experiences the least attraction from the nucleus.

3. **Establishing the Order**:
- Based on the analysis of each subshell's position relative to the nucleus and the number of inner electrons affecting the screening, we can establish the order of the screening effect as follows:
- **s > p > d > f**

4. **Conclusion**:
- The order of the screening effect of s, p, d, and f subshells is:
- **s > p > d > f**