Which one of the figures I and II represents the correct measure of atomic radius (r)?

Explanation

To determine which figure represents the correct measure of atomic radius, we need to understand the definition of atomic radius and analyze the two figures provided.

### Step-by-Step Solution:

1. **Understand the Definition of Atomic Radius**:
- The atomic radius is defined as the distance from the nucleus of an atom to the boundary of its valence shell, which contains the valence electrons.

2. **Analyze Figure I**:
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