Question

describe two changes that are harmful explain why you consider them harmful how can you prevent them

Answer 1

1.Rusting Of Iron:If bicycle chain get rusted,it may result in breakage of bicycle chain.
Prevention:Apply grease on it regularly.

2.Burning Of wood:When wood is burnt,it releases harmful gas and pollutes the earth.
Prevention:Use clean fuels like CNG,LPG,etc

Answer 2

The two chemical changes which are harmful to us are given below: Rusting of iron, Spoilage of food.

Explanation:

Rusting of iron:- It can cause ship harm and galvanizing can prevent it.

• When a piece of iron has been open for a while it acquires a brownish material film.
• This substance is called rust and is called the rusting process. Rusting is dangerous since iron artifacts are broken.
• Iron is the most commonly used material and so it is such a severe issue to rust.

Spoilage of food:- When a food item is carelessly kept, get spoiled.

• It is a chemical adjustment for us, and clearly dangerous.
• Microorganisms do not sustain when the humidity is elevated or low. As such food products contained in the fridge will not ruin. We should also hold them sealed so microbes don't have the opportunity to get in and damage everything.

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