The atomic radii ............ on moving down a group.

Explanation

To solve the question regarding the behavior of atomic radii when moving down a group in the periodic table, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Group**: Start by identifying a specific group in the periodic table. For this explanation, we will consider Group 1, which includes elements like Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), and Cesium (Cs).

2. **Examine Electron Configuration**: Look at the electron configuration of these elements.
- Lithium (Li) has 2 electrons in its first shell.
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