TEXTS FOR ADDITIONAL READING AND UNDERSTANDING

TEXT 1

 Point out the sentence which expresses the main idea of the text:

  1. The particle theory of matter.
  2. Energy and changes of state.
  3. The three states of matter.

All substances are made up of particles. The particles are so small that you cannot see them. In any substance, for example water, all the particles are the same as each other.

A substance can exist as a solid, a liquid, or a gas. These are the three states of matter. The particle theory explains the behavior of a substance in these three states.

Ice is water in the solid state. When a substance is in its solid state, the particles touch each other and are in a regular pattern. The particles are strongly attracted to each other. They don’t move around, but vibrate on the spot.

When a substance is in its liquid state the particles move around, in and out of each other. The particles are strongly attracted to each other, but are not in a regular pattern.

When a substance is in its gas state, the particles don’t touch each other. They are not attracted to each other. The particles move fast in all directions – there is no regular pattern.

If you had one particle of water, it would not behave as a solid or a liquid or a gas. Particles give a substance its properties when there are many of them.

 

1. Read the text again and decide whether the following statements are true or false:

  1. You cannot see them the particles with an unaided eye.
  2. All substances are made up of mixtures.
  3. In any one substance, for example water, all the particles are different from  each other.
  4. A substance can exist as a solid, a liquid, or a gas.
  5. The particle theory explains the behavior of a substance in three states.
  6. Ice is water in the gas state.
  7. When a substance is in its liquid state, the particles touch each other and are in a regular pattern.
  8. When a substance is in its solid state the particles move around, in and out of each other. They are strongly attracted to each other, but are not in a regular pattern.
  9. When a substance is in its gas state, the particles don’t touch each other. They are not attracted to each other. The particles move fast in all directions – there is no regular pattern.
  10. A particle gives a substance its properties even alone.