Correct order of vander waals radii among the following is:

Options

A. `N gt O gt F gt Ne`
B. `Ne gt N gt O gt F`
C. `N gt Ne gt O gt F`
D. `F gt Ne gt O gt N`

Answer

To determine the correct order of van der Waals radii among the given elements, we need to understand how van der Waals radii are influenced by atomic size and effective nuclear charge.

### Step-by-Step Solution:

1. **Understanding Van der Waals Radii**:
Van der Waals radii refer to the effective size of an atom when it is not bonded to another atom. It is influenced by the atomic size, which is affected by the number of electrons and the effective nuclear charge experienced by those electrons.

2. **Effective Nuclear Charge (Z-effective)**:
The effective nuclear charge is the net positive charge experienced by an electron in a multi-electron atom. As you move across a period from left to right, the number of protons in the nucleus increases while the shielding effect from inner electrons remains relatively constant. This leads to an increase in Z-effective, which pulls the outer electrons closer to the nucleus, resulting in a decrease in atomic size.

3. **Trends in Atomic Size**:
- As we move from left to right across a period, the atomic size decreases due to the increased Z-effective.
- Conversely, as we move down a group, the atomic size increases due to the addition of electron shells.

4. **Comparing Elements**:
Let's consider a hypothetical set of elements (for example, Nitrogen (N), Oxygen (O), Fluorine (F), and Neon (Ne)):
- Nitrogen (N) has the largest van der Waals radius because it is the furthest to the left in the period.
- Oxygen (O) is smaller than Nitrogen but larger than Fluorine.
- Fluorine (F) is smaller than both Nitrogen and Oxygen.
- Neon (Ne) is the smallest among these due to the increased Z-effective.

5. **Correct Order of Van der Waals Radii**:
Based on the above analysis, the correct order of van der Waals radii from largest to smallest is:
**N > O > F > Ne**

### Final Answer:
The correct order of van der Waals radii among the given elements is: **N > O > F > Ne**.