Can phase transition be used to test the purity of gold ?

Explanation

**Step-by-Step Solution:**

1. **Understanding Phase Transition**: Phase transition refers to the change of a substance from one state of matter to another, such as solid to liquid (melting) or liquid to gas (evaporation). In the context of gold, we focus on the melting point.

2. **Melting Point of Pure Gold**: Pure gold has a specific melting point, which is approximately 1064°C. This is a characteristic property of pure gold.

3. **Effect of Impurities**: When impurities are present in gold, they disrupt the uniform structure of the gold atoms. This disruption affects the melting point of the alloy. Specifically, the melting point of impure gold is lower than that of pure gold.

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