Correct order of radius of elements is: C, O, F, Cl, Br

Options

A. `Br gt Cl gt C gt O gt F`
B. `Br lt Cl lt C lt O lt F`
C. `Cl lt C lt O lt F lt Br`
D. `C gt F gt O gt Br gt Cl`

Explanation

To determine the correct order of atomic radii for the elements Carbon (C), Oxygen (O), Fluorine (F), Chlorine (Cl), and Bromine (Br), we need to consider their positions in the periodic table and the trends in atomic size.

### Step-by-Step Solution:

1. **Identify the Position of Elements in the Periodic Table:**
- Carbon (C) is in Group 14, Period 2.
- Oxygen (O) is in Group 16, Period 2.
- Fluorine (F) is in Group 17, Period 2.
- Chlorine (Cl) is in Group 17, Period 3.
- Bromine (Br) is in Group 17, Period 4.

2. **Understand the Trend in Atomic Radius:**
- **Across a Period:** As we move from left to right across a period, the atomic radius decreases. This is due to the increase in the effective nuclear charge (Z_eff), which pulls the electrons closer to the nucleus.
- **Down a Group:** As we move down a group, the atomic radius increases. This is because additional electron shells are added, which outweighs the increase in nuclear charge.

3. **Arrange the Elements Based on Their Atomic Radii:**
- **For C, O, F:**
- Carbon (C) has the largest radius, followed by Oxygen (O), and then Fluorine (F) has the smallest radius.
- **For Cl and Br:**
- Chlorine (Cl) has a smaller radius than Bromine (Br) because Bromine is in the fourth period and has more electron shells.

4. **Combine the Findings:**
- The order of atomic radii from largest to smallest is:
- Br > Cl > C > O > F

5. **Final Answer:**
- The correct order of radius of elements is: **Br > Cl > C > O > F**