The elements of which group are the biggest in size in respective periods?

Explanation

To determine which group of elements has the largest atomic size in their respective periods, we can follow these steps:

### Step 1: Understand Atomic Radius Trends
- **Atomic Radius Increases Down a Group**: As you move down a group in the periodic table, the atomic radius increases due to the addition of electron shells.
- **Atomic Radius Decreases Across a Period**: As you move from left to right across a period, the atomic radius decreases because of the increasing nuclear charge which pulls the electrons closer to the nucleus.

### Step 2: Identify the Groups
- The periodic table is divided into groups (columns) and periods (rows). Group 1 elements are known as alkali metals, and they include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).
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