(h) In froth process, the ore particles float because their surface is ____.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Froth Process**: The froth flotation process is a method used to separate hydrophobic materials from hydrophilic ones. It is commonly used in the extraction of metals from their ores.

2. **Role of Surface Properties**: In this process, the key factor that allows ore particles to float is their surface characteristics. Specifically, the surface of the ore particles must have certain properties that affect their interaction with water.

3. **Hydrophobic Nature**: The ore particles are typically treated with chemicals that make their surfaces hydrophobic. This means that the surface does not easily interact with water.

4. **Floating Mechanism**: Because the surface of the ore particles is not easily wetted by water, they tend to rise to the surface of the flotation cell when air bubbles are introduced. This results in the formation of a froth layer that can be skimmed off, containing the concentrated ore.

5. **Conclusion**: Therefore, in the froth process, the ore particles float because their surface is **not easily wetted by water**.

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