Which of the following are physical changes and which are chemical changes?
(a) Burning of a magnesium wire
(b) Freezing of water
(c) Rusting of iron
(d) Glowing of an electric bulb
Select the ascending order based on the time taken for the given changes to occur:
1. Glowing of bulb, 2. Germination of a seed, 3. Boiling of water, 4. Bursting of crackers