Match the types of colloidal systems given in Column I with the name given in Column II.
`{:(,"Column I","Column II"),(A.,"Solid in liquid",1."Foam"),(B.,"Liquid in solid ",2."Sol"),(C.,"Liquid in liquid ",3."Gel"),(D.,"Gas in liquid",4."Emulsion"):}`

Explanation

To solve the problem of matching the types of colloidal systems from Column I with the names in Column II, we will analyze each option step by step.

### Step 1: Identify the components in Column I
- **A. Solid in liquid**
- **B. Liquid in solid**
- **C. Liquid in liquid**
- **D. Gas in liquid**

### Step 2: Identify the components in Column II
- **1. Foam**
- **2. Sol**
- **3. Gel**
- **4. Emulsion**

### Step 3: Match each type of colloidal system

**A. Solid in liquid**
- Here, the solid particles are dispersed in a liquid medium. This type of colloid is known as a **Sol**.
- **Match: A - 2 (Sol)**

**B. Liquid in solid**
- In this case, liquid droplets are dispersed within a solid medium. This type of colloid is referred to as a **Gel**.
- **Match: B - 3 (Gel)**

**C. Liquid in liquid**
- This involves one liquid being dispersed in another liquid. The colloid formed here is called an **Emulsion**.
- **Match: C - 4 (Emulsion)**

**D. Gas in liquid**
- In this scenario, gas bubbles are dispersed in a liquid medium. This type of colloid is known as a **Foam**.
- **Match: D - 1 (Foam)**

### Final Matching
- A - 2 (Sol)
- B - 3 (Gel)
- C - 4 (Emulsion)
- D - 1 (Foam)

### Summary of Matches:
- A: Solid in liquid → Sol
- B: Liquid in solid → Gel
- C: Liquid in liquid → Emulsion
- D: Gas in liquid → Foam