Question 1:
(a) State whether the matter is a solid, liquid or gas.
(b) Give three other examples for each state of matter.
(c) Draw a table to show the arrangement and movement of particles for each state of matter.
Answer:
(a) (i) Bubble: Gas
(ii) Water: Liquid
(iii) Water weed: Solid
(iv) Aquarium: Solid
(v) Fish: Solid
(b) Solid: book, glass, cloth Liquid: oil, petrol, milk Gas: air, carbon dioxide and oxygen
(Any answers are accepted).
(c)
(a) State whether the matter is a solid, liquid or gas.
(b) Give three other examples for each state of matter.
(c) Draw a table to show the arrangement and movement of particles for each state of matter.
Answer:
(a) (i) Bubble: Gas
(ii) Water: Liquid
(iii) Water weed: Solid
(iv) Aquarium: Solid
(v) Fish: Solid
(b) Solid: book, glass, cloth Liquid: oil, petrol, milk Gas: air, carbon dioxide and oxygen
(Any answers are accepted).
(c)
Question 2:
How does the smell of cooking spread all over the house?
Answer:
Food smell spreads through diffusion of the smell particles into the air particles.
How does the smell of cooking spread all over the house?
Answer:
Food smell spreads through diffusion of the smell particles into the air particles.
Question 3:
State the kinetic theory of matter.
Answer:
Particles in matter always move and collide with one another.
State the kinetic theory of matter.
Answer:
Particles in matter always move and collide with one another.
Question 4:
Why is the temperature constant during the boiling of water?
Answer:
Temperature does not change because heat is used to overcome the force of attraction between the particles and thus, no change in temperature.
Why is the temperature constant during the boiling of water?
Answer:
Temperature does not change because heat is used to overcome the force of attraction between the particles and thus, no change in temperature.
Question 5:
In four season countries, the temperature may drop till below 0ºC during the peak of winter.
Why does the surface of the river or lake freeze?
Answer:
Air loses heat faster than water. Thus, air on the water surface and water on the surface will release heat. This will cause the water on the surface to freeze faster and act as a heat insulator. The frozen surface of water will prevent the water at the bottom from losing heat. Thus, not all the water in the lake or river will freeze.
In four season countries, the temperature may drop till below 0ºC during the peak of winter.
Why does the surface of the river or lake freeze?
Answer:
Air loses heat faster than water. Thus, air on the water surface and water on the surface will release heat. This will cause the water on the surface to freeze faster and act as a heat insulator. The frozen surface of water will prevent the water at the bottom from losing heat. Thus, not all the water in the lake or river will freeze.