Chemically borox is

Options

A. sodium metaborate
B. sodium orthoborate
C. sodium tetraborate decahydrate
D. sodium hexaborate

Explanation

To solve the question "Chemically borax is," we need to identify the correct chemical composition of borax.

### Step-by-Step Solution:

1. **Identify the Chemical Formula of Borax:**
- Borax is commonly known as sodium tetraborate. Its chemical formula is Na₂B₄O₇·10H₂O. This indicates that it contains sodium, boron, oxygen, and water molecules.

2. **Break Down the Chemical Formula:**
- The formula can also be represented as Na₂B₄O₅(OH)₄·H₂O. This shows that borax has a complex structure involving boron and hydroxide ions along with water.

3. **Determine the Hydration State:**
- The "10H₂O" in the formula indicates that borax is a decahydrate, meaning it contains 10 molecules of water for every formula unit of sodium tetraborate.

4. **Evaluate the Given Options:**
- The options provided include:
- Sodium metaborate
- Sodium orthoborate
- Sodium tetraborate decahydrate
- Sodium hexaborate
- Among these, sodium tetraborate decahydrate (Na₂B₄O₇·10H₂O) is the correct identification of borax.

5. **Conclusion:**
- Therefore, the correct answer is sodium tetraborate decahydrate.

### Final Answer:
Chemically, borax is sodium tetraborate decahydrate (Na₂B₄O₇·10H₂O).