Students can practice the best Class 7 Science MCQ and Changes Around Us Physical and Chemical Class 7 Science Curiosity Chapter 5 MCQ Online Test with Answers for exam preparation.
Class 7 Science Chapter 5 Changes Around Us Physical and Chemical MCQ
Changes Around Us Physical and Chemical MCQ Class 7
MCQ On Changes Around Us Physical and Chemical Class 7
Question 1.
Which of the following is a physical change?
(a) Burning of paper
(b) Rusting of iron
(c) Melting of ice
(d) Cooking of rice
Answer:
(a) Burning of paper
Question 2.
Which of the following changes is irreversible?
(a) Folding a paper
(b) Melting wax
(c) Making curd from milk
(d) Dissolving sugar in water
Answer:
(c) Making curd from milk
Question 3.
What is formed when earbon dioxide is passed through lime water?
(a) Oxygen
(b) Water
(c) Calcium carbonate
(d) Baking soda
Answer:
(c) Calcium carbonate
Question 4.
Which of these is a chemical change?
(a) Boiling of water
(b) Freezing of water
(c) Evaporation of water
(d) Burning of magnesium ribbon
Answer:
(d) Burning of magnesium ribbon
Question 5.
The turning of milk into curd is a:
(a) Physical change
(b) Reversible change
(c) Chemical change
(d) Change in state
Answer:
(c) Chemical change
Question 6.
Which of the following supports combustion?
(a) Nitrogen
(b) Oxygen
(c) Hydrogen
(d) Carbon dioxide
Answer:
(b) Oxygen
Question 7.
What kind of change occurs when paper is burnt?
(a) Physical change
(b) Reversible change
(c) Both physical and chemical
(d) Chemical change
Answer:
(d) Chemical change
Question 8.
Which is not necessary for combustion?
(a) Fuel
(b) Oxygen
(c) Water
(d) Heat
Answer:
(c) Water
Question 9.
What kind of change is observed when a candle is lit?
(a) Physical
(b) Chemical
(c) Both
(d) None
Answer:
(c) Both
Question 10.
Which gas turns lime water milky?
(a) Oxygen
(b) Hydrogen
(c) Nitrogen
(d) Carbon dioxide
Answer:
(d) Carbon dioxide
Question 11.
Which of these is a sign of chemical change?
(a) Change in shape
(b) Formation of new substance
(c) Change in size
(d) Temporary colour change
Answer:
(b) Formation of new substance
Question 12.
Which of these is a desirable chemical change?
(a) Rusting
(b) Decay of food
(c) Cooking of food
(d) Burning of clothes
Answer:
(c) Cooking of food
Question 13.
Chopping vegetables is what type of change?
(a) Chemical
(b) Physical
(c) Both
(d) Biological
Answer:
(b) Physical
Question 14.
What change occurs during the rusting of iron?
(a) Physical
(b) Reversible
(c) Chemical
(d) Periodic
Answer:
(c) Chemical
Question 15.
The formation of soil from rocks is an example of:
(a) Reversible physical change
(b) Chemical change only
(c) Both physical and chemical changes
(d) Only biological change
Answer:
(c) Both physical and chemical changes
Question 16.
Which of these shows a reversible physical change?
(a) Baking a cake
(b) Tearing a paper
(c) Freezing water
(d) Cooking rice
Answer:
(c) Freezing water
Question 17.
Which change involves the release of heat and light?
(a) Boiling water
(b) Freezing water
(c) Combustion
(d) Dissolving sugar
Answer:
(c) Combustion
Question 18.
Which of these is NOT a combustion product?
(a) Carbon dioxide
(b) Oxygen
(c) Water vapour
(d) Heat
Answer:
(b) Oxygen
Question 19.
What is the minimum temperature required to start combustion called?
(a) Flash point
(b) Melting point
(c) Ignition temperature
(d) Combustion limit
Answer:
(c) Ignition temperature
Question 20.
Which one of the following processes shows both physical and chemical change?
(a) Melting of wax
(b) Cutting vegetables
(c) Burning of candle
(d) Freezing of juice
Answer:
(c) Burning of candle
Changes Around Us Physical and Chemical Class 7 Assertion Reason Questions
Given below are two statements, one is labelled as Assertion (A) while the other is labelled as Answer: (R).
(a) Both (A) and (R) are true and (R) is correct explanation of (A).
(b) Both (A) and (R) are true and (R) is not correct explanation of (A).
(c) (A) is true but (R) is false.
(d) (A) is false but (R) is true.
1. Assertion (A): Magnesium ribbon burns and magnesium oxide is formed.
Answer: (R): Magnesium ribbon reacts to oxygen to produce Magnesium oxide + heat + light.
Answer:
(a) Both (A) and (R) are true and (R) is correct explanation of (A).
2. Assertion (A): Combustion is a chemical reaction where one substance react with air to form heat and light.
Answer: (R): The heat/light or both are produced and a new substance is formed.
Answer:
(a) Both (A) and (R) are true and (R) is correct explanation of (A).
3. Assertion (A): Change of water from liquid to steam on heating is a physical change.
Answer: (R): The state of water during heating remains the same and the change involves a change in composition.
Answer:
(c) (A) is true but (R) is false.
4. Assertion (A): Formation of rust is a chemical change.
Answer: (R): For the formation of rust, iron must be exposed to air and water.
Answer:
(b) Both (A) and (R) are true and (R) is not correct explanation of (A).
Changes Around Us Physical and Chemical Class 7 Fill in the Blanks
1. Depositing a layer of zinc on iron is _______.
Answer:
galvanisation
2. New substance is made by a _______ reaction.
Answer:
chemical
3. Rusting can be prevented by making _______.
Answer:
alloys
4. The hydrated iron is known as _______.
Answer:
iron oxide
5. Burning of magnesium is a chemical _______.
Answer:
change
6. Boiling water can be reversed to cold _______.
Answer:
water
7. Baking soda is added to vinegar, it forms _______ gas.
Answer:
carbon dioxide
8. Decay of food when storing is _______.
Answer:
desirable
9. New rock formation cannot be _______.
Answer:
reversed
10. _______ is cause of soil formation.
Answer:
Weathering
Changes Around Us Physical and Chemical Class 7 True or False
1. Example of chemical change is melting of ice.
Answer: False
2. Carbon dioxide turns lime water milky.
Answer: True
3. Paper is not a combustible substance.
Answer: False
4. Wrap a cloth on a burnt person to extinguish fire.
Answer: True
5. Now-a-days fuel consumption has increased in cars.
Answer: True
6. Change of milk in curd is undersirable change.
Answer: False
7. Heat and light are not produced in combustion.
Answer: False
8. Carbon is released from burning of wax of a candle.
Answer: True
9. The rust is a brown coloured sustance.
Answer: True
10. The fireflies emit light in late evening.
Answer: True