Period

Real World Example

Imagine you're organizing a bookshelf where each shelf holds a series of books that gradually change in topic from left to right. Just like these books transition smoothly from one subject to another, a period in the periodic table is a horizontal row where elements gradually change in properties as you move from left to right. Each book on the shelf represents an element in the period, starting with one topic (or property) and evolving into another by the end of the shelf, symbolizing how elements transition from metals to non-metals as you progress across the period.