Vidaara.orgClass 9 · Chemistry
CodeVID-C9-CHEM-01-T1-01
Assignment — States of Matter & their Properties
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- All questions are compulsory.
- Section A carries 1 mark each, Section B 2 marks, Section C 3 marks and Section D 5 marks.
- Show all reasoning for Sections B, C and D. For full solutions, raise your doubts with your teacher.
Section A — Multiple Choice Questions
5 × 1 = 5 marks
1.
Matter is anything that has mass and:
- A.colour
- B.occupies space
- C.is solid
- D.is visible
2.
Diffusion is fastest in:
- A.solids
- B.liquids
- C.gases
- D.crystals
3.
Which has the strongest force of attraction between particles?
- A.gas
- B.liquid
- C.solid
- D.vapour
4.
The fifth state of matter formed near −273°C is:
- A.plasma
- B.Bose-Einstein Condensate
- C.vapour
- D.gel
5.
Compressibility is greatest in a:
- A.solid
- B.liquid
- C.gas
- D.metal
Section B — Short Answer (2 marks)
3 × 2 = 6 marks
6.
State any two characteristics of the particles of matter.
7.
Why does a gas exert pressure on the walls of its container?
8.
Give one reason why solids are rigid but liquids can flow.
Section C — Short Answer (3 marks)
2 × 3 = 6 marks
9.
Compare solids, liquids and gases on the basis of shape, volume and compressibility.
10.
Explain, using the particle nature of matter, why the smell of food cooked in the kitchen spreads to other rooms.
Section D — Long Answer (5 marks)
1 × 5 = 5 marks
11.
Describe two experiments that prove (a) particles of matter have spaces between them and (b) particles of matter are continuously moving.
Answer Key
Section A — Multiple Choice Questions
- (B) occupies space
- (C) gases
- (C) solid
- (B) Bose-Einstein Condensate
- (C) gas
Section B — Short Answer (2 marks)
- Particles are very small with spaces between them, are in continuous motion (have kinetic energy), and attract one another (any two).
- Gas particles move rapidly in all directions and continuously strike the walls of the container; these collisions exert pressure.
- In solids particles are held in fixed positions by strong forces, so they only vibrate (rigid); in liquids the forces are weaker and particles can slide past one another, so liquids flow.
Section C — Short Answer (3 marks)
- Solid: fixed shape, fixed volume, almost incompressible. Liquid: no fixed shape, fixed volume, slightly compressible. Gas: no fixed shape, no fixed volume, highly compressible.
- Particles of matter are in continuous motion and have spaces between them. The aroma particles from the food move and diffuse, mixing with the moving air particles, and so travel from the kitchen into other rooms.
Section D — Long Answer (5 marks)
- (a) Spaces: Add sugar or salt to a full glass of water and stir; it dissolves and the water does not overflow, because the solute particles occupy the spaces between water particles. (b) Motion: Place a few crystals of potassium permanganate (or a drop of ink) at the bottom of a beaker of still water; without stirring, the colour slowly spreads throughout, showing the particles are continuously moving and diffusing into the water.
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