Question

Which of the below-given process is an example of chemical change?

• A. Twinkling of stars
• B. Cooking of vegetables
• C. Cutting of fruits
• D. Boiling of water

Answer 1

The correct option is B

Cooking of vegetables

Step 1: Explanation of the correct option

In the case of option B,

1. A chemical change occurs when a completely new product is produced by modifying its molecular composition.
2. These modifications are permanent and irreversible in nature.
3. Cooking vegetables is a chemical change because raw vegetables cannot be recovered after cooking.
4. The properties of cooked vegetables differ from those of raw vegetables, indicating a chemical change.

Step 2: Explanation for the incorrect options

In the case of option A,

1. Stars twinkle due to atmospheric refraction.
2. In a very simple term, it can be understood that the twinkling of stars occurs since light passes through many different layers.
3. These layers differ in temperature and density. As a result, light rays bent several times in various directions. Therefore, stars seem to twinkle

In the case of option C,

1. Fruit cutting is a physical change because no new substance is formed when the fruit is cut.
2. When a substance undergoes a change that does not alter its chemical composition, this is referred to as a physical change.

In the case of option D,

1. The boiling of water is an example of physical change because the gaseous water created is chemically similar to liquid water.
2. The molecular formula of water is the same as the molecular formula of gaseous water.

Hence, option B is the correct answer.