Question

TICK (THE ODD-ONE OUT GIVING REASON
1. Formation of biogas from animal dung, Melting of wax, Drying of wet clothes, Folding of filter paper
2. Reversible change, Temporary change, Permanent change, Glowing of an electric bulb
3. Change of milk into curd, Rusting of iron, Evaporation of water, Burning of wood
4. Formation of ice from water, Blowing of balloon, Ignition of a matchstick, Melting of an ice cream
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Answer 1

1. Formation of biogas from animal dung as it is the only chemical change in the group.
2. Permanent change as all the others refer to temporary changes.
3. Evaporation of water as it is the only physical change in the group.
4. Ignition of matchstick as it is the only chemical change