How do atomic structures (electron arrangement) change in a period with increase in atomic numbers, moving left to right?

Explanation

**Step-by-Step Solution:**

1. **Understanding Atomic Structure**:
- Atoms consist of a nucleus (containing protons and neutrons) and electrons that orbit around the nucleus in specific energy levels or shells.

2. **Electron Arrangement in a Period**:
- A period in the periodic table represents a horizontal row of elements. As we move from left to right across a period, we are adding more protons to the nucleus and more electrons to the outermost shell.

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