Identify the following on the basis of given atomic numbers:
19,15,14,8,4
Gas with valency of 2.

Explanation

To solve the question, we need to identify the elements corresponding to the given atomic numbers and then find the gas with a valency of 2. Here’s the step-by-step solution:

### Step 1: Identify the elements based on atomic numbers
- **Atomic number 19**: This corresponds to Potassium (K).
- **Atomic number 15**: This corresponds to Phosphorus (P).
- **Atomic number 14**: This corresponds to Silicon (Si).
- **Atomic number 8**: This corresponds to Oxygen (O).
- **Atomic number 4**: This corresponds to Beryllium (Be).
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