From the list of the elements Na, Mg, Al, Si, predict
The element which is tetravalent in its compounds

Answer

To determine which element from the list (Na, Mg, Al, Si) is tetravalent in its compounds, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the term "tetravalent":**
- Tetravalent means that the element has a valency of 4. This means it can form four bonds with other atoms.

2. **List the elements and their valencies:**
- Sodium (Na): The valency of sodium is 1.
- Magnesium (Mg): The valency of magnesium is 2.
- Aluminum (Al): The valency of aluminum is 3.
- Silicon (Si): The valency of silicon is 4.

3. **Identify the tetravalent element:**
- From the list, we see that:
- Sodium (Na) has a valency of 1 (not tetravalent).
- Magnesium (Mg) has a valency of 2 (not tetravalent).
- Aluminum (Al) has a valency of 3 (not tetravalent).
- Silicon (Si) has a valency of 4 (tetravalent).

4. **Conclusion:**
- Therefore, the element that is tetravalent in its compounds is **Silicon (Si)**.