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 vibrate
SOLID
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.
2. A substance consists of particles that can be similar or different.
3. There is space between particles.
4. The particles are constantly moving; the speed of these movements depends
on the temperature of the substance.
5. 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.
ST 204
NAME: ANSWER KEY
HR: ____ DATE: ____________
3. Define the following words.
A state of matter that has a fixed shape and volume and has strong bonds between
Solid
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
Boiling
Point
The temperature at which a substance changes from a solid to a liquid.
The temperature at which a substance changes from a liquid to a gas.
4. At 0 m altitude water boils at 100°C while at 1600m altitude water boils at 94°C.
5. Therefore, as the altitude increases less energy is needed to boil water.
6. What causes pressure in the atmosphere?
The force of the air molecules colliding with themselves and everything around them.
7. 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.