F, Cl and Br are elements each having seven valence electrons. Which of these: (i) has the largest atomic radius (ii) is most reactive? Justify your answer stating reason for each.

Explanation

To answer the question regarding the atomic radius and reactivity of the elements F (Fluorine), Cl (Chlorine), and Br (Bromine), we can follow these steps:

### Step 1: Determine the Atomic Radius
- **Atomic Radius Trend**: In the periodic table, as we move down a group (column), the atomic radius increases. This is because additional electron shells are added, which increases the distance between the nucleus and the outermost electrons.
- **Elements in Question**: Fluorine (F), Chlorine (Cl), and Bromine (Br) are all in Group 17 (the halogens).
- **Comparison**:
- Fluorine has 2 electron shells.
- Chlorine has 3 electron shells.
...