Select the correct answer for each question

1. A solid, like rock, has a:

   1.   ?    shape which is easy to change but its volume is fixed.
   2.   ?    shape which is fixed but it can change its volume.
   3.   ?    shape and a volume which are both easy to change.
   4.   ?    shape and volume which are both fixed.

2. All liquids:

   1.   ?    have a fixed volume and take the shape of their container
   2.   ?    have a fixed volume and a fixed shape
   3.   ?    will spread out until their volume has doubled.
   4.   ?    can change their volume but not their shape.

3. Gases:

   1.   ?    spread out until they fill the space around them.
   2.   ?    do not spread out.
   3.   ?    cannot be poured.
   4.   ?    keep their shape.

4. Which statement is not true?

   1.   ?    Scientists try to explain the world around us.
   2.   ?    Scientists do experiments to find out information.
   3.   ?    Scientists never need to use their imaginations.
   4.   ?    Scientists try to explain the results of experiments.

5. A theory is:

   1.   ?    an idea that explains evidence
   2.   ?    the result of an experiment.
   3.   ?    a chapter in a science book.
   4.   ?    the instructions for doing an experiment

6. How do scientists test theories?

   1.   ?    They see if their friends agree with them.
   2.   ?    Theories are always correct, so scientists do not need to test them.
   3.   ?    They use the theory to make predictions, and do experiments to see if the predictions are correct.
   4.   ?    They look in a different book.

7. Which of these things would a theory about solids, liquids and gases not have to explain?

   1.   ?    Why a sealed tin will explode if you heat it.
   2.   ?    Why the Sun feels warm.
   3.   ?    Why it is difficult to squash a solid.
   4.   ?    Why liquids can flow.

8. Everything is made up of:

   1.   ?    particles which are arranged differently in solids, liquids and gases.
   2.   ?    particles which are arranged in the same way in solids, liquids and gases
   3.   ?    water particles.
   4.   ?    nothing.

9. In a solid:

   1.   ?    the particles are very close together.
   2.   ?    the particles are as far apart as possible.
   3.   ?    the particles are quite close together.
   4.   ?    there are no particles.

10. In a liquid:

    1.   ?    the particles are very close together.
    2.   ?    the particles are as far apart as possible.
    3.   ?    the particles are quite close together.
    4.   ?    there are no particles.

11. In a gas:

    1.   ?    the particles are held tightly in place by bonds.
    2.   ?    there are no particles.
    3.   ?    the particles are free to move anywhere
    4.   ?    the strong bonds let the particles move past each other.

12. If you put a drop of coloured liquid into a glass of cold water and leave it to stand without stirring, what will happen to the colour?

    1.   ?    It will float on the surface.
    2.   ?    It will spread out in the water within a second or two
    3.   ?    It will sink to the bottom and never spread out.
    4.   ?    It will spread out in the water very slowly.

13. A smell can spread across a room even if there are no air currents. This is called:

    1.   ?    convection
    2.   ?    diffusion
    3.   ?    contraction
    4.   ?    distraction

14. How fast do things spread out in liquids compared to gases?

    1.   ?    They spread out faster in liquids.
    2.   ?    They spread out faster in gases.
    3.   ?    They spread out at exactly the same speed.
    4.   ?    They do not spread out in liquids at all.

15. If you put some sugar into cold water and leave it without stirring, the sugar will eventually dissolve and mix with the water. This happens because:

    1.   ?    particles are extremely small.
    2.   ?    sugar particles are bigger than water particles.
    3.   ?    water particles are bigger than sugar particles.
    4.   ?    particles in a liquid are always moving around.

16. Pressure in a container full of gas is caused by:

    1.   ?    particles sticking to the walls.
    2.   ?    particles bumping into the walls.
    3.   ?    particles sticking to each other.
    4.   ?    particles falling to the bottom of the container

17. You can increase the pressure in a container full of gas by:

    1.   ?    making the container smaller.
    2.   ?    making the container bigger
    3.   ?    cooling the gas.
    4.   ?    taking some of the gas out.

18. If you put more gas into a container the pressure increases because:

    1.   ?    the particles all cool down.
    2.   ?    there is more space for the particles to move around.
    3.   ?    more particles fall to the bottom of the container.
    4.   ?    there are more particles, so there are more collisions with the wall.

19. The air is being sucked out of this bottle. Why is it collapsing?

    1.   ?    There is more air pressure inside than outside.
    2.   ?    There is more air pressure outside than inside.
    3.   ?    There are more particles inside it.
    4.   ?    Air particles are sticking to the walls and pulling them in.

20. Which of these materials will have similar properties?

    1.   ?    air, oxygen, ice
    2.   ?    water, iron, air
    3.   ?    iron, stone, wood
    4.   ?    oil, water, wood