Is Matter Around Us Pure

Name the process associated with the following
(a) Dry ice is kept at room temperature and at one atmospheric pressure.
(b) A drop of ink placed on the surface of water contained in a glass spreads
throughout the water.
(c) A potassium permanganate crystal is in a beaker and water is poured
into the beaker with stirring.
(d) A acetone bottle is left open and the bottle becomes empty.
(e) Milk is churned to separate cream from it.
(f) Settling of sand when a mixture of sand and water is left undisturbed
for some time.
(g) Fine beam of light entering through a small hole in a dark room,
illuminates the particles in its paths.