Physical Science

Heat and Matter Review

Within a substance,

• A: all particles have the same energy

• B: all particles move at the same rate

• C: some particles move faster than others

• D: the particles that make up the substance do not move

On Earth, most thermal energy comes from:

• A: the Sun

• B: objects moving against each other

• C: electric stoves

• D: atomic reactions in the earth’s core

A pan of water is on a hot stove burner. The hot burner

transfers energy to the particles

• A: of water at the bottom of the pan

• B: of water in the middle of the pan

• C: of water at the top of the pan

• D: that make up the pan itself

As particles of matter gain more energy, the matter is:

• A: having a fall in temperature

• B: contracting

• C: expanding

• D: slowing down the motion of its particles

As temperature rises, the most expansion of particles occurs

in:

• A: water

• B: solids

• C: liquids

• D: gases

To keep train tracks from twisting during temperature changes, between the tracks

there are:

• A: spaces

• B: metal joints

• C: concrete joints

• D: brass joints

An example of conduction would be:

• A: clay used for walls

• B: Layered clothing

• C: birds feathers

• D: ironing clothes

The insulator that keeps a polar bear warm is:

• A: water

• B: air

• C: a polar fleece jacket

• D: global warming

Convection takes place from the movement of:

• A: liquids only

• B: solids only

• C: gases only

• D: liquids or gases

Heat energy alwaysalways flows from:

• A: cold hot

• B: hot cold

What is Heat?

• The flow of energy from warmer matter to cooler matter

What is Thermal Energy?

• The total energy of the particles that make up any matter

What is Temperature?

• A measure of the average motion of particles in a substance / object

Matter has:

• Mass:– The amount of particles that make up matter

• Volume:– The amount of space that matter takes up

Is heat matter?

• No, heat is not matter, it is energy!

Is there a transfer of matter when heat is transferred?

• No, there is a transfer of energy when heat is transferred!

True / False

• When you touch a glass of cold water, heat energy is transferring from your skin to the glass.

True

True / False

• When you put an ice cube in water, heat energy is transferring from the water to the ice cube.

True

Small pot of water and big pot of water are on a stove:

• Which will boil first and why?

– The small pot will boil first because it has less matter. Less matter takes less energy to increase in temperature.

What is absolute zero?

• Absolute zero is –273 degrees Celsius, and is the temperature at which particles almost stop moving

Expands vs. Contracts

• Matter ________ when it is heated

• Matter ___________ when it is cooled

EXPANDS

CONTRACTS

Closer vs. Farther

• Particles get ____________ during expansion

• Particles get ____________ during contraction

farther

closer

Extreme Expansion!

• Why did my bike tire explode when I left it in my car last week?

• It got too hot, the air inside of it expanded until it burst!

Water: the exception to the expansion / contraction rule

• What happens to liquid water as it cools from room temperature to freezing?– The particles in the liquid contract until just

before they freeze. Then they form rings as they freeze, and actually expand!

Conduction or Convection?

• Ice cube melts in your hand

• Conduction (direct transfer of heat)

• Liquid wax floats then sinks then floats again in a lava lamp

• Convection (transfer of heat by moving particles)

Radiation

• Give some examples of transfer of heat by radiation:

• The sun warms your hand with it’s UV rays

Great Job!

• Study hard for the test, any of these questions, and many others, could appear on it!!!!!!!