What is the basic difference between adsorption and absorption.

Explanation

**Step-by-Step Text Solution:**

1. **Definition of Adsorption:**
- Adsorption is the process in which molecular species accumulate at the surface of a solid or liquid rather than within the bulk of the material. This means that only the molecules at the outer surface interact with the adsorbate, while the molecules inside remain unaffected.

2. **Example of Adsorption:**
- A common example of adsorption is when a piece of chalk is placed in water. After a brief period, only the outer surface of the chalk becomes wet, while the inner part remains dry. This illustrates that only the surface molecules are involved in the adsorption process.

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