From the electronic configurations Na (2, 8, 1), Mg (2, 8, 2) and Al (2, 8, 3), answer the following questions:
What is the number of valence electrons in each element?

Explanation

To determine the number of valence electrons in Sodium (Na), Magnesium (Mg), and Aluminium (Al) based on their electronic configurations, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Electronic Configurations**:
- Sodium (Na): 2, 8, 1
- Magnesium (Mg): 2, 8, 2
- Aluminium (Al): 2, 8, 3
...