Give oxidation state of all boron atom in borax.

Explanation

To determine the oxidation state of all boron atoms in borax (Na₂B₄O₇), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Chemical Formula**:
The chemical formula for borax is Na₂B₄O₇. This indicates that there are 2 sodium (Na) atoms, 4 boron (B) atoms, and 7 oxygen (O) atoms in the compound.

2. **Assign Known Oxidation States**:
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