CBSE Class 7 Science Physical and Chemical Changes Worksheet Set A

Question. Using the density column and the data table, predict which of these will FLOAT on the oil?

a) Sample A
b) Sample B
c) Sample C
d) Sample D

Answer : B

Question. Two identical spring scales are arranged as shown. If a weight is suspended as shown in the figure what will happen?

a) Spring on the left will stretch more.
b) Spring on the right will stretch more.
c) Both springs will stretch the same distance.
d) One cannot tell which spring will stretch more.

Answer : A

Question. Which of the following is NOT a cyclic change?
a) formation of a rainbow
b) ocean tides
c) the phases of the moon
d) the seasons of the year

Answer : A

Question. Which of the following is a chemical change?
a) Grinding of rice
b) Breaking of a window pane
c) A bud changing into a flower
d) Powdering of sugar crystals

Answer : C

Question. Distilled water is called pure because_____________.
a) it contains dissolved salts
b) it boils at exactly 100degree C and freezes at exactly 0degreeC
c) it contains dissolved oxygen
d) it can be produced only in a laboratory

Answer : B

Question. The flow chart gives the method of separation of four substances P, Q, R and S of which one is water. What are P, Q, R and S?  

a) A
b) B
c) C
d) D

Answer : C

Question. In the arrangement shown, which of the following materials will make lime water turn milky when kept for a few days?

a) Damp boiled rice
b) Dry wood pieces
c) Roasted peanuts
d) Charcoal

Answer : A

Question. In the figure below, P, Q and R represent three different physical states of a substance. A direct change from the state represented by R to that represented by P would be _________.

a) evaporation
b) condensation
c) melting
d) sublimation

Answer : D

Which of the following can be classified as a chemical change?
a) lighting of a matchstick
b) melting of ice
c) condensation of water
d) separation of salt from water

Answer : A

Question. Students in a laboratory are told not to taste any chemicals (even common salt) in the laboratory. What is the MAIN reason?
a) The chemicals bought for the laboratory are not pure.
b) Chemicals may have got mixed or wrongly labelled.
c) Chemicals are very expensive and should not be wasted.
d) The chemicals may get spoilt if they are touched.

Answer : B

Question. Which of these is a chemical change?

a) mixing sand in water
b) magnetizing a piece of iron
c) a copper container getting tarnished
d) evaporation of water

Answer : B

Question. The period of development in the mother's womb before birth is called the gestation period. Study the gestation periods and life spans of some animals and answer the question

a) there is no relation whatsoever between gestation period and life span.
b) the longer the gestation period, the shorter the life span with some exceptions.
c) the longer the gestation period, the longer the life span with some exceptions.
d) animals with the shortest and longest gestation periods have longer life spans.

Answer : A

Question. A metallic circular disc having a hole as shown, is heated. What would it look like when it expands after heating (shown by the dotted lines)?

Answer : D

Question. In which part of the atmosphere is the ozone layer?
The earth’s atmosphere is divided into different layers - the stratosphere, mesosphere and ionosphere as shown here. Study the figure and answer the question.     

a) below the stratosphere
b) in the stratosphere
c) in the mesosphere
d) in the ionosphere

Answer : B

Question. Among the animals in the table, which have gestation periods more than 6 months?
The period of development in the mother's womb before birth is called the gestation period. Study the gestation periods and life spans of some animals and answer the question

a) Only elephants
b) Only horses and elephants
c) Only horses, elephants, men and bears
d) Only horses, elephants, men, lions and bears

Answer : C

            Questions

            Very Short Answer

Q1)      Define galvanisation?

Q2)      How stainless steel is made?

Q3)      What happens when carbon dioxide passed through lime water?

Q4)      What is rust?

Q5)      Name the two types of changes?

            Short Answer

Q6)      Why explosion of a fireworks is a chemical change?

Q7)      What do you understand by the rusting of iron?

Q8)      Why is protecting the ozone layer important?

Q9)      What do you mean by the term chemical reaction?

Q10)    Why does not stainless steel rust?

            Long Answer

Q11)    Write short note on crystallization?

Q12)    Distinguish between physical and chemical change?

Q13)    Difference between rusting and corrosion?

Q14)    What are the steps taken when the new product may accompany a chemical change?

Q15)    Explain about the chemical reaction and its concepts?

Please click on below link to download CBSE Class 7 Science Physical and Chemical Changes Worksheet Set A