Give reasons for the following.
When a solid substance is subjected to heating, it disappears without leaving any liquid.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks why a solid substance can disappear when heated without leaving any liquid behind.

2. **Defining Sublimation**: The key process involved here is called sublimation. Sublimation is the transition of a substance from the solid phase directly to the gas phase without passing through the liquid phase.

3. **Heating the Solid**: When a solid substance is heated, the energy from the heat causes the molecules in the solid to gain energy and move faster. In some cases, this energy is sufficient for the molecules to break free from the solid state and enter the gas state directly.

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