Not a Chemical Change - Freezing of Water

Explanation:

Chemical Change:
A chemical change, also known as a chemical reaction, is a process that results in the formation of new substances with different chemical properties. In a chemical change, the arrangement of atoms is altered, and new bonds are formed or broken. Some common examples of chemical changes include burning, rusting, and digestion.

Physical Change:
A physical change, on the other hand, is a process that does not involve the formation of new substances. In a physical change, the state, shape, or size of a substance may be altered, but the chemical composition remains the same. Examples of physical changes include melting, freezing, boiling, and dissolving.

Freezing of Water:
The freezing of water is a physical change rather than a chemical change. When water freezes, it undergoes a phase change from a liquid to a solid state. The molecules in water slow down and come closer together, forming a crystalline structure. However, the chemical composition of water (H2O) remains the same before and after freezing.

Key Points:
- Freezing of water is a physical change.
- In a physical change, the chemical composition remains the same.
- Water freezes at 0 degrees Celsius (32 degrees Fahrenheit).
- Freezing involves a phase change from a liquid to a solid state.
- The molecules in water slow down and form a crystalline structure during freezing.

Conclusion:
Among the given options, the freezing of water is the only process that does not involve a chemical change. The other options, such as ripening of fruits, curdling of milk, and digestion of food, all involve chemical reactions that result in the formation of new substances.