Question

question 3
which of the following is an example of a purely chemical change?

• the shaping of a lump of clay.
• the explosion of fireworks.
• the sanding of a piece of wood.
• the melting of ice cream.

Explanation:

A chemical change produces new substances, while physical changes only alter form/state without new matter. Shaping clay, sanding wood, and melting ice cream are physical changes (no new substances formed). Fireworks explosions involve combustion reactions that create new gases, light, and solid residues, which is a chemical change.

Answer:

B. The explosion of fireworks.