CLASSIFY THE FOLLOWING AS PHYSICAL OR CHEMICAL CHANGES .also justify it. :
a.eating a vada.
b.frying an egg.
c.a petrol can is left open in the garage.the vapour fills the garage.
d.melting wax.
e.melted wax turns into vapour and then burns.
f.rani applied henna to her palms.
g.raghav poured milk in his cornflakes.
h.raja finds his cake of soap getting smaller each week.
i.sam burnt the toaster.
j.the milk turned sour.
k.mrs.iyer cooked rice and made a tasty pudding.
l.carbon dioxide is cooled until it turns into solid "dry ice"which is used for refrigetion.
Chemical changes are those which are irreversible in nature. So those process which cannot be undone are-
a) Eating vada. (Eating cannot be undone)
b) Frying an egg. (Cooking is irreversible)
e) Melted wax turns into vapours and then burns. (Burning is chemical reaction)
f) Rani applied henna to her palms. (Even if henna is removed, the palms will acquire colour)
h) Raja finds his cake of soap getting smaller each week. (Soap dissolves in water and cannot be obtained again)
i) Sam burnt the toaster. (Burning is chemical reaction)
j) The milk turned sour. (Chemical reaction took place in presence of bacteria)
k) Mrs. Iyer cooked rice and made tasty pudding. (Cooking is irreversible)
Physical change are those changes which can be reversed.
c) a petrol can is left open in the garage and the vapours fills the garage.
d) Melting of wax. (Solidification of wax can take place again)
e) Raghav poured milk in his cornflakes. (Milk can be obtained back by filtering)
f) Carbon dioxide is cooled until it turns into solid 'dry ice' which is used for refrigeration. (By changing temperature carbon dioxide can be recollected).
a) Eating vada. (Eating cannot be undone)
b) Frying an egg. (Cooking is irreversible)
e) Melted wax turns into vapours and then burns. (Burning is chemical reaction)
f) Rani applied henna to her palms. (Even if henna is removed, the palms will acquire colour)
h) Raja finds his cake of soap getting smaller each week. (Soap dissolves in water and cannot be obtained again)
i) Sam burnt the toaster. (Burning is chemical reaction)
j) The milk turned sour. (Chemical reaction took place in presence of bacteria)
k) Mrs. Iyer cooked rice and made tasty pudding. (Cooking is irreversible)
Physical change are those changes which can be reversed.
c) a petrol can is left open in the garage and the vapours fills the garage.
d) Melting of wax. (Solidification of wax can take place again)
e) Raghav poured milk in his cornflakes. (Milk can be obtained back by filtering)
f) Carbon dioxide is cooled until it turns into solid 'dry ice' which is used for refrigeration. (By changing temperature carbon dioxide can be recollected).