CBSE Class 7 Science Physical and Chemical Changes MCQs

Physical and Chemical changes

Question. A change in which a substance undergoes changes in its physical properties is called 
(a) Chemical change  
(b) physical change 
(c) No change  
(d) Biological change

Answer : B

Question. When carbon dioxide is passed through lime water , then lime water becomes
(a) milky
(b) shiney  
(c) silvery  
(d) Golden yellow

Answer:  A

Question. Brown colour of the apple  after cutting is
(a) physical change  
(b) chemical change 
(c) no change  
(d) biological change

Answer : B

Question.  Ozone layer protects us from harmful
(a) Ultraviolet radiation
(b) Infrared Radiation 
(c) Visible Radiation  
(d) Heat radiation

Answer:  A

Question. The process of depositing a layer of one metal over another metal surface to protect it from rusting is called
(a) Galvanisation
(b) Crystallisation
(c) amalgamating 
(d) Neutralisation

Answer:  A

Question. For protecting iron pipes from corrosion, they are coated with
(a) Zinc 
(b) Copper  
(c) Aluminium  
(d) Silver

Answer:  A

Question. Metal that is made by mixing iron with carbon, nickel and manganese is called 
(a) Stainless steel  
(b) German silver 
(c) Nichrome  
(d) Eureka 

Answer:  A

Question. The process of obtaining Salt by the evaporation of sea water is called
(a) Crystallisation  
(b) Neutralisation
(c) Galvanisation 
(d) Amalgamation

Answer:  A

Question. Blue colour of the copper sulphate solution changes to Green colour when an iron nail is dropped into it due to the formation of
(a) Iron sulphate  
(b) copper chloride 
(c) Copper iron sulphate  
(d) Iron chloride

Answer:  A

Question. When Magnesium ribbon is burnt in oxygen, the product obtained is
(a) Magnesium chloride  
(b) Magnesium sulphate 
(c) Magnesium oxide  
(d) Iron chloride

Answer : C

Question. Magnesium hydroxide, obtained when Magnesium oxide is dissolved in water, is
(a) a Base  
(b) An acid 
(c) an indicator  
(d) a dissolving agent

Answer:  A

Question. When Magnesium ribbon is burnt in candle flame it burns with
(a) brilliant red light  
(b) Brilliant yellow light
(c) Brilliant white light 
(d) Brilliant Green light

Answer : C

Question. How crystal of pure substances are obtained?
(a) By crystallization
(b) By chromatography
(c) By peptization
(d) By all these methods

Answer:  A

Question. A chemical change may bring
(a) evolution of gas
(b) change in colour
(c) change in taste
(d) all of these

Answer:  D

Question. In chemical change
(a) Change is reversible
(b) Molecules of a substance change
(c) Molecules of the substance do not change
(d) Substance remain same

Answer : B

Question. The process of forming substances in their pure state from their solution is known as:
(a) galvanisation
(b) neutralisation
(c) crystallisation
(d) all of these

Answer : C

Question. A change of state from one form to another is a
(a) physical change
(b) chemical change
(c) biological change
(d) state variation

Answer:  A

Question. The shipping industry has to bear huge financial loss because of rusting of ships. The rusting of ships occur because:
(a) the body of ship is always in contact with water.
(b) the air around the ship is humid.
(c) presence of salts in sea water speed up the process of rusting.
(d) All of the above

Answer:  D

Question. Which characteristic best describes a physical change?
(a) Composition changes
(b) Composition stays the same
(c) Form stays the same
(d) Mass is lost

Answer : B

Question. Which is the best method to prevent rusting?
(a) Painting
(b) Greasing
(c) Galvanization
(d) Precipitation

Answer : C

Question. When you leave a piece of iron in the open for some time, it acquires a film of brownish substance. The substance is called:
(a) acid
(b) base
(c) rust
(d) none of these

Answer : C

Question. Few example of chemical changes are:
(a) burning of coal
(b) food getting spoiled
(c) formation of curd
(d) all of these

Answer:  D

Question. The process of depositing a layer of zinc over iron is known as
(a) aluminisation
(b) galvanisation
(c) fertilisation
(d) ironing

Answer : B

Question. Which of the following is an irreversible change ?
(a) Physical
(b) Rusting
(c) Chemical
(d) None of these

Answer : C

Question. Neutralisation is a:
(a) physical change
(b) chemical change
(c) both (a) and (b)
(d) none of these

Answer : B

Question. Which of the following changes is accompanied by sound?
(a) Photosynthesis
(b) Spoilage of food
(c) Explosion of fire works
(d) None of these

Answer : C

Question. Rusting of iron objects is faster in:
(a) deserts
(b) coastal areas
(c) both (a) and (b)
(d) none of these

Answer : B

Question. The reason for a physical change to be named as such is that the:
(a) change occurs only in physical properties
(b) transfer of energy takes place
(c) is a reversible change
(d) All of the above

Answer:  A

Question. When wax vapours burns then smoke and carbon dioxide are formed which are new substances, is a:
(a) physical change
(b) chemical change
(c) both (a) and (b)
(d) none of these

Answer : B

Question. Properties like size, shape, colour, state of a substance are
(a) chemical properties
(b) mental properties
(c) physical properties
(d) physico-chemical properties

Answer : C

Question. Which among the following is a physical change?
(a) Cutting a log of wood in small pieces
(b) Burning of wood
(c) Ripening of fruit
(d) Cooking of food

Answer:  A

Question. Which property stays the same during physical and chemical changes?
(a) Density
(b) Shape
(c) Mass
(d) Arrangement of particles

Answer : C

Question. A change in which the original substance can be obtained back by change of conditions is called:
(a) reversible change
(b) physical change
(c) chemical change
(d) Both (a) and (b)

Answer:  D

Question. Which of the following changes can easily be reversed?
(a) Chemical Change
(b) Physical Change
(c) Both physical and chemical changes
(d) Neither physical nor chemical change

Answer : B

Question. Rusting occurs when iron is exposed to
(a) oxygen and water
(b) soil and rain
(c) breeze and sunlight
(d) salt water and clouds

Answer:  A

Question. Formation of a compound is
(a) Temporary change
(b) Physical change
(c) Chemical change
(d) Reversible change

Answer : C

Question. For rusting:
(a) Only moisture is required
(b) Only air is required
(c) Both air and moistured are required
(d) None of these

Answer : C