Chemical Change:
A chemical change, also known as a chemical reaction, occurs when the substances involved undergo a transformation that results in the formation of new substances with different chemical properties. In a chemical change, the atoms in the substances rearrange to form new bonds, resulting in the creation of entirely new substances.

A) Frying eggs:
Frying eggs is an example of a chemical change. When eggs are fried, the heat causes the proteins in the eggs to denature and coagulate. This chemical reaction results in the formation of solid cooked eggs with a different texture and taste compared to raw eggs. The heat causes the proteins to undergo a structural change, forming new bonds and creating a new substance.

B) Melting ice cream:
Melting ice cream is an example of a physical change, not a chemical change. When ice cream melts, it changes from a solid to a liquid, but no new substances are formed. The change is purely physical, as the molecules in the ice cream simply gain energy and move apart, resulting in a change in state.

C) Making a paper airplane:
Making a paper airplane involves folding and shaping a piece of paper. This is also a physical change, as no new substances are formed. The paper is simply manipulated to create a new shape, but the chemical composition of the paper remains the same.

D) Wetting a towel:
Wetting a towel is another example of a physical change. When a towel is wetted, water molecules are absorbed into the fabric, causing it to become damp. However, the chemical composition of the towel remains unchanged. The water molecules are simply interacting with the fibers of the towel on a physical level.

Conclusion:
Out of the given options, frying eggs is the only example of a chemical change. The heat applied during the frying process causes the proteins in the eggs to undergo a chemical reaction, resulting in the formation of solid cooked eggs. Melting ice cream, making a paper airplane, and wetting a towel are all examples of physical changes where no new substances are formed.

Chemical Change:
A chemical change refers to a process in which one or more substances are transformed into new substances with different properties. This change involves the breaking and formation of chemical bonds, resulting in the creation of new molecules. These changes are typically irreversible.

Explanation:
Among the given options, frying eggs is the only activity that involves a chemical change. Let's understand why the other options do not involve a chemical change:

Melting ice cream:
Melting ice cream is a physical change rather than a chemical change. It involves a change in the state of matter from solid to liquid. The molecular structure of the ice cream remains the same, only the arrangement of particles changes.

Making a paper airplane:
Making a paper airplane also does not involve a chemical change. It is a physical change that involves folding, bending, and shaping the paper. The paper retains its chemical composition, and no new substances are formed.

Wetting a towel:
Wetting a towel is another example of a physical change. It involves the absorption of water by the towel fibers, but the chemical composition of the towel remains unchanged.

Frying eggs:
Frying eggs is the only option that involves a chemical change. When eggs are exposed to heat, the proteins in the egg white and yolk undergo a chemical reaction called denaturation. Denaturation causes the proteins to unfold and reorganize, resulting in the formation of new compounds with different properties. The heat also causes the water present in the eggs to evaporate, leading to the formation of steam. Overall, frying eggs is a chemical change as it involves the transformation of substances into new substances with different properties.

In conclusion, among the given options, frying eggs is the only activity that involves a chemical change. The other options involve physical changes where the substances retain their chemical composition.