Question

Describe two changes that are harmful. Explain why they considered them harmful. how can you prevent them?​

Answer 1

Answer:

Two changes which are harmfulare: 1) Rusting of iron - it cancause damage to ships - can beprevented by galvanizing. The two chemical changes which areharmful to us are given below: Rusting on metal objects as itdeteriorates the metal surface and decreases the efficiency ofit.

Answer 2

• Combustion of petroleum as it cause a threat to the environment.
• Burning of Plastic gives out harmful gasses.