ST 204 NAME: ANSWER KEY HR: ____ DATE: ______

Review of states of matter, temperature, pressure and melting & boiling point

Text pp. 175 – 183 & 188

1. What am I?

a) I have a definite shape & volume. SOLID

b) My shape & volume are not definite. GAS

c) The bonds in between my particles are very strong. SOLID

d) My particles slide one on top of the other. LIQUID

e) I am unique to a substance. CHARACTERISTIC PROPERTY

f) I am found in between all particles SPACE

g) 50g, 200ml & 4m NON- CHARACTERISTIC PROPERTY

h) From 20°C to 25°C AMBIENT TEMPERATURE

i) Density & finger prints CHARCTERISTIC PROPERTIES

j) My particles vibrateSOLID

2. Give the 5 ideas behind the Particle Theory. Include a small drawing for each idea.

  1. All substances are made of very small particles.

  1. A substance consists of particles that can be similar or different.

  1. There is space between particles.

  1. The particles are constantly moving; the speed of these movements depends on the temperature of the substance.

  1. The particles of a substance either attract or repel each other; the strength of the attraction or repulsion depends on the type of particles in the substance.

3. Define the following words.

Solid / A state of matter that has a fixed shape and volume and has strong bonds between its particles.
Liquid / A state of matter that has a fixed volume, but takes the shape of its container. It has weaker bonds between its particles than solids do.
Gas / A state of matter that has no fixed shape or volume. It has very weak bonds between its particles which are very far apart from each other.
Mass / The amount of matter contained in a substance.
Volume / The amount of space a substance occupies.
Celsius / The SI unit for temperature.
Pressure / The force exerted over a certain area.
Melting Point / The temperature at which a substance changes from a solid to a liquid.
Boiling Point / The temperature at which a substance changes from a liquid to a gas.

4. At 0m altitude water boils at100°Cwhile at 1600m altitude water boils at 94°C.

5. Therefore, as the altitude increases less energy is needed to boil water.

  1. What causes pressure in the atmosphere?

The force of the air molecules colliding with themselves and everything around them.

  1. Why does it take less energy to boil water at higher altitudes?

There are fewer air particles, therefore there is less force and less pressure exerted on the water, so that makes it easier for it to turn into a gas (boil).

8. As the temperature increases, particles move faster since they have more energy.