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## Friday, April 29, 2011

### Temperature, Heat, and the Particle Theory

Temperature, Heat, and the Particle Theory
1.         What is a theory and can they be changed?

A theory is an explanation based on all the available information.  A theory can be changed when new evidence is discovered.

The Particle Theory

2.         According to the Particle Theory, what four characteristics are common to all matter?

According to the Particle Theory:

1.  All matter is made up of tiny particle too small to see.
2.  These tiny particles are always moving
3.  The tiny particles have energy
4.  The more energy the particles have the faster they move

3.         Use the Particle Theory of Matter to explain why pollen grains move around when placed in a glass of water.

Pollen grains move around in a glass of water because they are being pushed around by
the invisible particles in water.

Heat and Temperature

4.         Using the particle theory, explain Heat and Temperature.

The invisible particles in matter move because they have energy.  This energy is called heat. When these particles get more energy they move faster.  This creates more heat.

Temperature is a measure of the average energy of motion of the particles of a substance.

Expansion and Contraction

5.         Use the particle theory to explain the Expansion and Contraction of matter

Expansion:      When a substance is heated, its invisible particle get more energy so they move faster and they move further apart.  This results in an increase in volume (size) for the substance.

Contraction:    When a substance is cooled, its invisible particles lose energy.  They slow down and move closer together.  This results in a decrease in volume (size) for the substance.

States of Matter

6.         What are the 3 possible states of all Matter?

The 3 states of matter are Solid, Liquid, and Gas

8.         Using Figure 4, Identify the properties (characteristics) of Solids, Liquids, and Gases.

Properties of Solids
1.  a set volume
2.  a rigid shape
3.  they cannot flow like a gas or liquid
4.  the particles move but only vibrate

Properties of Liquids
1.  a set volume
2.  they take the shape of the container they are in
3.  a liquid can flow
4.  its particle are free to move around

Properties of Gases
1.  it will fill any container and take the shape of the container
2.  a gas will flow
3.  its particles are free to move around
4.  its particle are much further apart than solids or liquids
Understand and Apply

9.   What is Brownian motion?  What important evidence did it provide to scientists?

The movement of pollen grain in a glass of water is referred to as Brownian Motion.  This motion is cause by the water particles.

This movement helped scientist prove that their Particle Theory – that all matter is made of tiny particle that are always moving.

10.       In your own words describe the difference between HEAT and TEMPERATURE.

Heat is another name a particle energy.
Temperature is a measurement of the average energy of moving particles

11.       Use the Particle Theory to explain how a clinical thermometer works.

In a clinical thermometer, the tiny particles of ethyl alcohol inside the bulb of the thermometer are heated by a person’s body temperature. This increase in energy causes the particle of ethyl alcohol to move faster and further apart.  As a result, the ethyl alcohol in the bulb of the thermometer begins to expand.  As the alcohol expands it moves up the bore of the thermometer.  The alcohol stops moving up the bore when it reaches a constant temperature.

12.       How can you use a bottle of perfume in a room to show that the molecules in a gas are in constant motion?

When a bottle of perfume is opened its smell is transferred through the air by the particles that make up the air.