How does number of valency vary on moving from left to right
In the second period of a periodic table

Explanation

To understand how the number of valency varies when moving from left to right in the second period of the periodic table, we can break down the information step by step.

### Step 1: Identify the Elements in the Second Period
The second period of the periodic table includes the following elements:
- Lithium (Li)
- Beryllium (Be)
- Boron (B)
- Carbon (C)
...