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Worksheets7th class
Total questions: 16
Worksheet time: 8mins
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
Both (b) and (c) are correct
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.
All of the above
Expansion on heating and contraction on cooling of metals is a:
chemical change
Physical change
irreversible change
None of these
Which of the following changes is accompanied by sound?
Photosynthesis
Spoilage of food
Explosion of fire works
None of these
Which of the following statements is correct?
Evaporation is a chemical change
Digestion of food is a chemical change
Burning of paper is a physical change
All of the above
Which of the following statements is correct?
When coal is burnt no new substance is produced
Rust is not formed in the absence of air or oxygen
The fizz that comes out when a soda bottle is opened is due to a chemical change.
Respiration is a physical process
Which of the following statements is correct?
Cutting of wood into pieces is a chemical change.
Conversion of manure from leaves is a physical change.
Iron pipes coated with zinc do not rust easily.
All of the above
Which of the following is the name of the process of obtaining salt by evaporation of sea water?
Amalgamation
Sublimation
Crystallization
Galvanization
Read the following two statements carefully and choose the correct options.
(i) Cutting of wood is considered as a chemical change
(ii) Crystallization is a physical change
Statement (i) is correct while statement (ii) is incorrect
Statement (ii) is correct while statement (i) is incorrect.
Both statements are correct
Both statements are incorrect
Which of the following is not a chemical change?
Digestion of food
Conversion of liquified petroleum gas into gas on opening the cylinder.
Photosynthesis
Production of biogas from animal waste
Identify the acid present in tamarind.
Tannic acid
Lactic acid
Tartaric acid
Citric acid
Which acid is present in vinegar?
Formic acid
Acetic acid
Citric acid
Malic acid
What is injected into the skin when an ant bites?
Acid
Base
Salt
Water
Which of the following chemicals are used to neutralize the basic nature of soil?
Quicklime
Organic matter
Slaked lime
Baking soda
Which of the following is an antacid?
Mg(OH)2
NaOH
H2SO4
H2O
Which of the following statements is correct?
Acids turn blue litmus red.
Bases turn red litmus blue.
Water changes the colour of a litmus.
Both (A) and (B
