Which periods are called the short periods and
which are called the long periods? Why?

Explanation

To determine which periods in the periodic table are referred to as short periods and which are considered long periods, we need to analyze the number of elements present in each period.

### Step-by-Step Solution:

1. **Identify the Periods in the Periodic Table:**
The periodic table consists of seven periods:
- Period 1
- Period 2
...