Amongst the elements of period 3 :
Na Mg Al Si P S Cl Ar
Indicate the atomic numbers of the following type of elements:
Nonmetals

Explanation

To find the atomic numbers of nonmetals in Period 3, we will follow these steps:

### Step-by-Step Solution:

1. **List the Elements in Period 3**:
The elements in Period 3 are Sodium (Na), Magnesium (Mg), Aluminium (Al), Silicon (Si), Phosphorus (P), Sulfur (S), Chlorine (Cl), and Argon (Ar).

2. **Identify Nonmetals**:
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