Science MCQs

Acid rain forms when pollutants react chemically with rainwater.

Chopping changes the wood's size and shape but not its chemical identity.

Burning converts wood into ash smoke and gases new substances.

Margarine is produced by hydrogenating vegetable oils.

Plastic bags do not decompose easily and cause pollution.

Reusable cloth bags are eco-friendly and replace many disposable bags.

Heating sugar strongly causes decomposition leaving solid carbon.

It is irreversible; carbon cannot be converted back to sugar easily.

Hydrogenation adds hydrogen atoms to unsaturated oils making them solid.

Chemical changes are usually permanent and form new substances.