`Ca^(2+)` has a smaller ionic radius than `K^(+)` because it has ................ .

Explanation

To solve the question of why `Ca^(2+)` has a smaller ionic radius than `K^(+)`, we can break it down into the following steps:

### Step 1: Understand the Ionic Forms
- **Calcium Ion (`Ca^(2+)`)**: Calcium loses two electrons to form a `Ca^(2+)` ion.
- **Potassium Ion (`K^(+)`)**: Potassium loses one electron to form a `K^(+)` ion.

### Step 2: Analyze the Position in the Periodic Table
- **Calcium (Ca)** is located in Group 2 (alkaline earth metals) and Period 4 of the periodic table.
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