Why is a small quantitiy of mixture used in the borax beat test?

Explanation

### Step-by-Step Solution:

1. **Understanding the Borax Bead Test**: The borax bead test is a qualitative analysis technique used to identify the presence of certain metal ions in a sample. The test involves heating a mixture of borax (sodium borate) and the sample in a flame.

2. **Composition of Borax**: The chemical formula for borax is Na2B4O7·10H2O. When heated, it loses water and forms a colorless, transparent glassy bead known as a borax bead, which is essentially a mixture of sodium metaborate and boric anhydride.

3. **Application of the Sample**: A small amount of the sample (mineral or salt) is then applied to the surface of the borax bead. The bead is then exposed to a flame, which causes the sample to react and produce characteristic colors.

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