The correct order of increasing atomic size of element N F Si & P.

Options

A. `N lt F lt Silt P`
B. ` F gt N lt P lt Si `
C. ` F lt N lt P lt Si `
D. ` F lt N lt Si lt P `

Answer

To determine the correct order of increasing atomic size for the elements nitrogen (N), fluorine (F), silicon (Si), and phosphorus (P), we can follow these steps:

### Step 1: Understand the Periodic Trends
Atomic size generally decreases from left to right across a period and increases from top to bottom within a group. This is due to the increasing nuclear charge that pulls the electrons closer to the nucleus as you move across a period, and the addition of electron shells as you move down a group.

### Step 2: Identify the Groups and Periods
- Nitrogen (N) and Phosphorus (P) are in Group 15 (or Group V).
- Fluorine (F) is in Group 17 (or Group VII).
- Silicon (Si) is in Group 14 (or Group IV).
- Nitrogen and Fluorine are in Period 2.
- Silicon and Phosphorus are in Period 3.

### Step 3: Compare the Atomic Sizes
1. **Fluorine (F)**: Being in Group 17 and Period 2, it has a small atomic size due to its high electronegativity and the effective nuclear charge.
2. **Nitrogen (N)**: Also in Group 15 and Period 2, nitrogen is larger than fluorine because it has fewer protons, resulting in a weaker pull on the electrons.
3. **Phosphorus (P)**: In Group 15 and Period 3, phosphorus is larger than nitrogen because it has an additional electron shell.
4. **Silicon (Si)**: In Group 14 and Period 3, silicon is larger than phosphorus due to having more electrons and an additional shell.

### Step 4: Establish the Order
Based on the above comparisons, we can establish the following order of increasing atomic size:
- Fluorine (F) < Nitrogen (N) < Phosphorus (P) < Silicon (Si)

### Final Answer
The correct order of increasing atomic size for the elements N, F, Si, and P is:
**F < N < P < Si**

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