Melting of ice:
When ice melts, it undergoes a physical change, not a chemical change. The molecules in the ice are rearranged, but the chemical composition remains the same. The process of melting ice is a phase change from a solid to a liquid state.

Boiling of water:
Similar to the melting of ice, boiling water is also a physical change. The heat energy causes the water molecules to gain enough kinetic energy to break the intermolecular forces and convert from a liquid to a gas state. The chemical composition of water remains unchanged during this process.

Burning of wood:
The burning of wood is a chemical change. When wood burns, it undergoes a process called combustion. The heat energy breaks down the complex organic compounds present in wood, such as cellulose and lignin, into simpler substances like carbon dioxide, water vapor, and ash. This chemical reaction involves the rearrangement of atoms and the formation of new chemical bonds, resulting in a change in the chemical composition of the wood.

Chopping of vegetables:
Chopping vegetables is a physical change. It involves cutting the vegetables into smaller pieces, but the chemical composition of the vegetables remains the same. The process of chopping does not involve any chemical reactions.

Conclusion:
Among the given options, the burning of wood (Option C) is the only example of a chemical change. It involves a combustion reaction that results in the formation of new substances with different chemical properties. The other options, melting of ice, boiling of water, and chopping of vegetables, are all examples of physical changes where the chemical composition remains unchanged.