1. Chemical changes are: (a) Growth of a plant (b) Rusting of iron (c) Cooking of food (d) Digestion of food (e) Burning of a candle

    Chemical changes are:
    (a) Growth of a plant

    (b) Rusting of iron

    (c) Cooking of food

    (d) Digestion of food

    (e) Burning of a candle

    See less
    • 0
  2. Pure substances—Water, bread, sugar and gold. Mixtures—Steel, plastic, paper, talc, milk and air.

    Pure substances—Water, bread, sugar and gold.
    Mixtures—Steel, plastic, paper, talc, milk and air.

    See less
    • 0
  3. Cutting of trees→ Physical change Melting of butter in a pan → Physical change Rusting of almirah → Chemical change Boiling of water to form steam → Physical change Passing of electric current through water, and water breaking down into hydrogen and oxygen gas → Chemical change Dissolving common salRead more

    Cutting of trees→ Physical change
    Melting of butter in a pan → Physical change
    Rusting of almirah → Chemical change
    Boiling of water to form steam → Physical change
    Passing of electric current through water, and water breaking down into hydrogen and oxygen gas → Chemical change
    Dissolving common salt in water → Physical change
    Making a fruit salad with raw fruits → Physical change
    Burning of paper and wood → Chemical change

    See less
    • 0
  4. Crystallisation technique is used to purify solid with some impurities in it. Example: Salt from sea-water.

    Crystallisation technique is used to purify solid with some impurities in it. Example: Salt from sea-water.

    See less
    • 0