Which of the following represents a chemical change ?
1 . Magnetization of iron
2. Condensation of liquid
3. Burning of fuel
4. Rusting of iron
Select the correct answer using the code given below :
Code :

Options

A. 1 and 2
B. 2 and 3
C. 3 and 4
D. 1 and 4

Explanation

To determine which of the given options represents a chemical change, we need to analyze each option based on the definition of a chemical change. A chemical change is characterized by the formation of a new substance and is typically irreversible.

1. **Magnetization of iron**: This is a physical change because it does not result in the formation of a new substance. The iron remains iron, just in a different physical state (magnetized).

2. **Condensation of liquid**: This is also a physical change. When a gas condenses into a liquid, no new substance is formed; the chemical composition remains the same.

3. **Burning of fuel**: This is a chemical change. When fuel burns, it reacts with oxygen to produce new substances (like carbon dioxide and water), and this process is generally irreversible.

4. **Rusting of iron**: This is another example of a chemical change. Rusting occurs when iron reacts with oxygen and moisture in the air to form iron oxide (rust), which is a new substance, and this process is also irreversible.

Based on this analysis, the options that represent a chemical change are:

- **3. Burning of fuel**
- **4. Rusting of iron**

Thus, the correct answer is: **3 and 4**.