The periodicity is related to the electronic configuration. That is, all chemical and physical properties are a manifestation of the electronic configuration of the elements.
The atomic and ionic radii generally decrease in a period from left to right. As a consequence, the ionization enthalpies generally increase and electron gain enthalpies become more negative across a period. In other words, the ionization enthalpy of the exterme left element in a period is the least and teh electron gain enthalpy of the element on the exterme right is the highest negative. This results into high chemical reactivity at the two extermes and the lowest in he centre. Similarly down the group, the increase in atomic and ionic radii result in gradual decrease in ionization enthalpies and a regular decrease (with exception in some third period elements) in electron gain enthalpies in the case of main group elements.
The loss and gain of electrons can be co-related with the reducting and oxidising behaviour, and also with metallic and non-metallic character respectively, of the elements.
Considering the elements `B, C, N, F` and `Si`, the correct order of their non-metallic character is:

Options

A. `B gt C gt Si gt N gt F`
B. `Si gt C gt B gt N gt F`
C. `F gt N gt C gt B gt Si`
D. `F gt N gt C gt Si gt B`

Explanation

To determine the correct order of non-metallic character for the elements Boron (B), Carbon (C), Nitrogen (N), Fluorine (F), and Silicon (Si), we need to analyze their positions in the periodic table and understand the trends in non-metallic character.

### Step-by-Step Solution:

1. **Identify the Elements and Their Positions**:
- Boron (B) is in Group 13, Period 2.
- Carbon (C) is in Group 14, Period 2.
- Nitrogen (N) is in Group 15, Period 2.
- Fluorine (F) is in Group 17, Period 2.
- Silicon (Si) is in Group 14, Period 3.

2. **Understand the Trend in Non-metallic Character**:
- Non-metallic character increases as you move from left to right across a period. This is due to the increasing electronegativity and the tendency to gain electrons.
- Non-metallic character decreases as you move down a group because the atomic size increases, making it less favorable for these elements to gain electrons.

3. **Rank the Elements Based on Their Non-metallic Character**:
- **Fluorine (F)**: Highest non-metallic character as it is the most electronegative element.
- **Nitrogen (N)**: Next highest non-metallic character as it is also a non-metal and is located to the left of Fluorine.
- **Carbon (C)**: Comes next as it is a non-metal, but lower than Nitrogen.
- **Boron (B)**: Has a lower non-metallic character compared to Carbon and Nitrogen, as it is a metalloid.
- **Silicon (Si)**: Lowest non-metallic character among these elements as it is also a metalloid and located in the third period.

4. **Final Order of Non-metallic Character**:
- The correct order from highest to lowest non-metallic character is: **F > N > C > B > Si**.

### Conclusion:
Thus, the correct order of non-metallic character for the elements B, C, N, F, and Si is: **Fluorine (F) > Nitrogen (N) > Carbon (C) > Boron (B) > Silicon (Si)**.