Two elements having valency 4.

Explanation

To solve the question of identifying two elements that have a valency of 4, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Valency**:
- Valency is the measure of an element's ability to combine with other elements, which is determined by the number of electrons in its outer shell (valence electrons).

2. **Identify Valence Electrons**:
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