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WorksheetsClass 7 Physical and Chemical Changes
Total questions: 10
Worksheet time: 5mins
Which of the following is a physical change?
Rusting of iron
Melting of wax
Combustion of magnesium ribbon
Burning of candle
Which of the following is a chemical change?
Cooking of vegetables
Crumpling of paper
Cutting of fruits
Boiling of water
A chemical change may involve
Change in color only
Change in temperature only
Evolution of gas only
Any or all of the above
Conversion of milk to curd involves (choose all that applies)
Change in color
Change in taste
Milk changes from liquid to semi-solid
Irreversible change
Which of the following processes is used to prevent articles from rusting?
Crystallization
Galvanization
Evaporation
Electolysis
When ice is heated, it changes to water and water on further heating gets converted to steam. What happens when steam is condensed?
A new substance is formed
No new substance is formed
Gaseous phase changes to liquid phase
Color Changes
Which of the following will be observed if an apple slice is left exposed to air?
It under goes oxidation and become brown in colour
Appearance of brown colour on the surface of apple slice is caused by a chemical reaction between air and enzymes
It dries up
None of the options apply
The shipping industry has to bear huge financial loss because of rusting of ships. The rusting of ships occur because:
The body of ship is always in contact with water
The air around the ship is humid.
Presence of salts in sea water speed up the process of rusting.
The ship is not painted properly
Expansion on heating and contraction on cooling of metals is a
Chemical Change
Physical Change
Irreversible change
Reversible change
Which of the following changes is accompanied by sound?
Photosynthesis
Spoilage of food
Explosion of fire works
Crumpling of paper
