What is meant in the periodic table by a period ?

Explanation

**Step-by-Step Text Solution:**

1. **Understanding the Layout of the Periodic Table:**
- The periodic table is organized into rows and columns. The rows are called periods, while the columns are known as groups or families.

2. **Definition of a Period:**
- A period refers to a horizontal row of elements in the periodic table. Each period represents a different energy level of electrons in the atoms of the elements.

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