Which of the following changes cannot be reversed?
(a) Blowing of a balloon
(b) Folding a paper to make a toy aeroplane
(c) Rolling a ball of dough to make roti
(d) Baking cake in an oven
(e) Drying a wet cloth
(f) Making biogas from cow dung
(g) Burning of a candle
The following changes cannot be reversed:
(d) Baking of a cake is irreversible.
(f) Making biogas from cow dung is irreversible.
(g) Burning of a candle is irreversible.
(NOTE: there is a difference between burning of candle and melting of candle)
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