A potter working on his wheel shaped a lump of clay into a pot. He then baked the pot in an oven. Do these two acts lead to the same kind of changes or different? Give your opinion and justify your answer.
The two acts lead to the different kind of changes. Shaping of pot on a wheel is a physical, reversible change while baking the pot in an oven is an irreversibl
A substance present in plants which itself does not undergo any change but helps in changing water and carbon dioxide into food. A) Flower B) Bud C) Leaf D) Chlorophyll
CHLOROPHYLL
Rusting of iron is an example of:
CHEMICAL CHANGES/ REACTION
Which one of the steps while burning a candle is not reversible? (a) Melting of solid wax (b) liquid wax changes into vapours (c) Wax vapour bums into flame (d) All of these
c) Wax vapour bums into flame
CHOOSE
A
Choose the answer
B. it contracts
Rohan tore a sheet of paper into pieces and then burnt them. Identify the irreversible change taking place in the process. A) Tearing the sheet into pieces. B) Burning the pieces C) Both tearing and burning the pieces
C) Both tearing and burning the pieces
The brown coloured deposition on an iron box when kept in humid air for some days is called: A) Dust B) Rust C) Argon D) All the above
RUST
CHOOSE
C
Which kind of change it will be, if a sac of cement gets wet completely and left in open? A) Irreversible change B) Reversible change C) Biological change D) Desirable change
A) Irreversible change
Heat can change: (a) state of an object (b) size of an object (c) solubility of a substance (d) all of these
all of these
choose the option
B
A piece of iron is heated till it becomes red-hot. it then becomes soft and is beaten to a desired shape. What kind of changes are observed in this process-reversible or irreversible?
reversible
Name the gas which is produced when washing soda reacts with lemon juice. A) Oxygen B) Nitrogen C) Argon D) Carbon dioxide E) None of these
D
While making chapati, Radhika observed the following changes, which among the following is a reversible change? A) Changing of flour into dough. B) Rolling of chapati. C) Baking of chapati. D) Eating a chapati.
ROLLING OF CHAPATI
Paheli had bottle of pickle. She tried to open the metal cap to taste it but could not do so. She then took a bowl of hot water and immersed the upper end of the bottle in it for five minutes. she was able to open why?
On immersing in hot water, the metal cap expands in size hence it can be removed easily.
Iron blade of spade is made slightly smaller than the wooden handle because: A) Iron ring contracts on heating. B) Iron ring expands on heating. C) Iron ring remains the same on heating. D) Wooden handle expands on heating.
B) Iron ring expands on heating.
Which among the following is incorrect statement? A) Rusting of iron is irreversible change. B) Ripening of fruits is a chemical change. C) Breaking of glass is a reversible change. D) All the above E) None of these
C) Breaking of glass is a reversible change.
Making of curd from milk is which kind of change? A) Unwanted change B) Reversible change C) desirable change D) No change
C) desirable change
CHOOSE THE ODD ONE OUT :melting of butter, burning of paper, boiling of water, cutting of aluminium foil in half.
burning of paper