CH 15-17 Heat

when an object absorbs or gives off heat, the internal energy of the object ________ or _________

increases, decreases

as the temperature in a solid _______, the space between atoms ________

increases, increases

thermal expansion

the change in size of a substance due to an increase or decrease of the space between particles

gas

A state of matter with no definite shape or volume; random motion

an ________ in pressure increases the boiling point of water

increase

what does the amount of heat flow depend on?

-temperature difference -material -amount of material

Freezing point of water in Celsius

0 degrees

Boiling point of water in Celsius

100 degrees

________ degrees Celsius is the most dense point because that's when water starts to freeze

4

water crystallizes and expands between _______ degrees C and ________ degrees C

4, 0

solid

A form of matter that has a definite shape and volume with an ordered structure

liquid

A state of matter that has no definite shape but has a definite volume; molecules are free to move relative to one another

radiation

Heat transfer through infrared radiation (a type of electromagnetic wave)

condensation

a phase change from a gas to a liquid

evaporation

a phase change from a liquid to a gas

freezing

a phase change from a liquid to a solid

melting

a phase change from a solid to a liquid

the seasons are caused by

The tilt of the Earth's axis

convection

The transfer of heat by the movement of a heated fluid

temperature

a measure of the average KE of a substance's particles

fluid pressure

a measure of the average force exerted by a substance's particles over a unit of surface area

A liter of hot water will cool to room temperature faster in a black pot red pot steel pot

black pot

non-metals have _______ electrons that can't contribute to energy transfer

bound

objects that radiate relatively well

absorb radiation relatively well

energy is _______ during a phase change from solid to liquid

absorbed

energy is _______ when a phase change from a liquid to gas occurs

absorbed

When a block of ice at zero degrees Celsius melts, the ice A) absorbs energy from its environment. B) releases energy to its environment. C) absorbs energy and gets warmer. D) releases energy and gets warmer. E) absorbs energy but does not change its temperature.

absorbs energy but does not change its temperature

evaporation occurs

at the surface of a liquid

heat energy is measured in units of _______ and ________

calories and joules

the inside surface of a glass window becomes wet when the temperature outside is

colder

a thermos bottle controls heat transfer by

conduction, convection, radiation

a _________ in pressure decreases the boiling point of water

decrease

warm air rises because faster moving molecules tend to move to regions of less

density and pressure

changes of phase require a transfer of ________

energy

what is heat?

energy in transit because of a temperature difference

boiling

evaporation below surface of a liquid

true/false: ceiling fans reduce room temperature

false

true/false: heat transfer always occurs from a cold object to a hot one

false

true/false: in a glass of water, all of the molecules have the same speed

false

true/false: liquid water is less dense than ice

false

true/false: phase of matter doesn't depend on the temperature and pressure exerted on it

false

true/false: radiation needs matter through which to travel

false

true/false: when heat is added to boiling water, its temperature changes

false

thermal convection applies mainly to

fluids

condensation occurs when

gas molecules strike liquid and become part of the liquid

in order to change the temperature of a substance, ________ must be added or removed

heat

conduction

heat transfer by contact

most substances expand when _______ and contract when _________

heated, cooled

compared to a giant iceberg, a hot cup of coffee has

higher temperature but less internal energy

when a substance is said to have high specific heat capacity, what does that mean?

it will take a lot of heat energy to increase or decrease the temperature of the substance

rank metals, non-metals, and gases from highest thermal conductivity to lowest conductivity

metals, non-metals, gases

metals have ______ electrons that can contribute to energy transfer

mobile

a good reflector of radiation is a

poor absorber of radiation

A good heat conductor is A) a poor insulator. B) a good insulator. C) neither a poor nor a good insulator.

poor insulator

heat travels from the Sun to the Earth by

radiation

energy is _____ when a phase change from liquid to solid occurs

released

energy is ______ when a phase change from gas to liquid occurs

released

consider a closed, sealed air placed on a hot stove. The contained air undergoes an increase in

temperature and pressure

What does 0 degrees Kelvin mean?

temperature where the substance has no kinetic energy; lowest possible temperature

heat energy

the amount of thermal energy transferred between substances that are at different temperatures

specific heat

the quantity of heat required to change the temperature of a unit mass of the substance by 1 degree Celsius

what happens when you heat water that is at 0 degrees Celsius

the temperature increases until it reaches 100 degrees Celsius

what happens when you heat ice that is at 0 degrees Celsius

the temperature stays constant until all the ice is melted

what happens when you heat water that's at 100 degrees Celsius

the temperature stays constant until all the water is boiled

what happens when you heat ice that is at -40 degrees Celsius

the temperature will increase until the ice reaches its melting point

internal energy

the total energy of all of a substance's particles (atoms and molecules)

specific heat is a measure of a substance's _________ _________

thermal inertia

true/false: both the freezing point and melting point are the same for a pure substance

true

true/false: during phase changes, temperature stays constant

true

true/false: evaporation is a cooling process because the more energetic molecules are able to escape the liquid

true

true/false: every object above absolute zero (0 Kelvin) radiates

true

true/false: if you attach two different materials together, they'll expand and cool at different rates

true

true/false: radiant energy is a mixture of frequencies and wavelengths which depend on the object's temperature

true

true/false: the higher the average KE, the higher the temperature

true

true/false: thermal energy=internal energy

true

true/false: when there is a temperature difference between objects in proximity, heat transfer between them can never be stopped, it can only be slowed down

true

When snow forms in clouds, the surrounding air A) warms. B) cools. C) neither warms nor cools.

warms