Heat

Kelvin is defined by:

Absolute zero (-273˚C): At absolute zero, molecules stop vibrating entirely, i.e. the theoretical lowest temperature possible

During a cooling change of state, thermal energy is __________ as bonds are __________ between molecules/atoms, and the ___________ between molecules/atoms ________________.

Released, formed, distance, decreases

Heating changes of state ___________ energy to _________ ________, while cooling changes of state ___________ energy in the ______________ ____ _______.

Require, break bonds, release, formation of bonds

If two objects are in thermal contact for long enough, they will eventually reach the ________ _________________ (__________ _________________).

Same temperature, thermal equilibrium

Matter commonly exists in three states: ________, ________, and _____.

Solid, liquid, gas

Conduction occurs in:

Solids, liquids and gases

Solid to gas:

Sublimation

Average kinetic energy is directly proportional to _________________.

Temperature

During a change of state, there is no change in _______________ because:

Temperature, the average kinetic energy has not increased/decreased

Fahrenheit is defined by:

The blood temperature of a living human (100˚F)

Thermal energy is:

The combined potential energy and kinetic energy that is due to the vibration of particles within an object.

Specific heat capacity is:

The heat energy required to raise the temperature of 1kg of a substance by 1 degree Kelvin.

Latent heat is:

The heat energy that is absorbed/released during a change of state

Convection occurs in:

Liquids and gases only, as particles in solids are locked in place

The change in temperature depends on the _________ of the object (____), the amount of ________ _______________ to or from the object (____), and the nature of the _____________ (its ____________ ________ ______, ____).

Mass, m, heat transferred, Q, material, specific heat capacity, c

Solid to liquid:

Melting

The amount of latent heat required (____) depends upon the _________ of the substance (________ ______ ___________, ____) and the ______ of the substance (___).

Q, nature, latent heat capacity, L, mass, m

____________ is the only way heat can flow in a vacuum.

Radiation

An example of convection involves:

A burner heating a liquid: The liquid at the bottom gets heated and becomes less dense (particles are more spread out), and this liquid rises, displacing more dense liquid to the bottom where it is heated: forms a convection current

An example of conduction involves:

A candle heating a wire: The flame supplies thermal energy to the particles closest to it, and these particles vibrate faster, which causes neighbouring particles to vibrate faster: thermal energy is thus transferred along the object

Temperature is:

A measure of the average kinetic energy of the particles in a substance.

Energy can be added to or removed from a system without causing a _________ ____ _____. The energy that is added or removed causes a _________ ________ ______________.

Change of state, change in temperature

Gas to liquid:

Condensation

A good ____________ allows the transfer of thermal energy to occur easily, while a good _______________ does not allow the transfer of thermal energy to occur easily.

Conductor, insulator

Gas to solid:

Deposition

Temperature determines the _______________ of thermal energy transfer between two objects in thermal contact.

Direction

Any objects that have temperature will radiate ______________________ _______: If the temperature is above 100˚C, EM radiation is mostly ____________ and ________________, and if the temperature is below 100˚C, EM radiation is mostly ______________.

Electromagnetic waves, visible, ultraviolet, infrared

_______________ involves an increase in temperature, while __________ does not.

Evaporation, boiling

Most solids, liquids and gases _________ when heated.

Expand

Liquid to solid:

Freezing

Heat flows from a region of ___________ temperature to a region of __________ temperature.

Higher, lower

Particles within objects of higher temperatures have a __________ average kinetic energy, while particles within objects of lower temperatures have a __________ average kinetic energy.

Higher, lower

Celsius is defined by:

The temperature at which water freezes (0˚C) and the temperature at which water boils (100˚C)

Heat is:

The thermal energy that is absorbed, released or transferred between objects.

Radiation is:

The transfer of thermal energy from a region of higher temperature to a region of lower temperature by means of electromagnetic waves/light

Conduction is:

The transfer of thermal energy from a region of higher temperature to a region of lower temperature by particle collision and without the transfer of matter

Convection is:

The transfer of thermal energy in a fluid from a region of higher temperature to a region of lower temperature by the mass movement of particles themselves.

An increase in the temperature of an object is due to an increase in its ____________ ___________.

Thermal energy

During a heating change of state, thermal energy is ________ to __________ bonds between molecules/atoms, and the ____________ between molecules/atoms _____________.

Used, break, distance, increases

Liquid to gas:

Vaporisation