Changes around us Worksheet-3

Changes around us Worksheet-3

Multiple -Choice Question:

1. Substances that dissolve in water are called:

(A) Soluble          (B) Insoluble        (C) Solutions

2. Which substance can be dissolved completely in water?

(A) Salt                 (B) Sand               (C) Flour

3. Which of the following is an irreversible change?

(A) Flower to Fruit                           (B) Ice to water

(C) Melted ice-cream                      (D) Sheet of paper to paper boat

4. Are melting, freezing, boiling, evaporation and condensation always reversible changes?

(A) Yes                 (B) Only sometimes     (C) No

5. Cooling causes a material to ________.

(A) None of these                            (B) Expand

(C) Contract                                     (D) Stretch

6. Water expands on heating. It is due to:

(A) Due to the faster vibration of molecules

(B) Due to expansion of molecules

(C) Due to the collision of molecules

7. How could we change burnt paper back into its original form?

(A) Scrape off the soot

(B) We can't

(C) Cool it

8. Expansion gaps are kept in railway tracks because of:

(A) Expansion of rails in hot weather

(B) Contraction of rails in hot weather

(C) Contraction of rails in cold weather

(D) Expansion of rails in cold weather

9. Baking a cake is an example of:

(A) Physical change

(B) Irreversible change

(C) Chemical change

(D) Both chemical and irreversible

10. When we walk through a waterlogged area, our clothes get wet. Can this change be reversed?

(A) No, it can’t be reversed

(B) Yes, it can be reversed

(C) On wetting, water molecules break into hydrogen and oxygen so it can’t be reversed

Answer Key:

1. (A)
2. (A)
3. (A)
4. (A)
5. (C)
6. (A)
7. (B)
8. (A)
9. (D)
10. (C)