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
(a) Burning of a magnesium wire-Chemical change
(b) Freezing of water- Physical change
(c) Rusting of iron- Chemical change
(d) Glowing of an electric bulb- Physical change