Core B Particles

Solid

State of matter where particles are close and joined to specific neighbours, with fixed volume and shape

Liquid

State of matter where particles are joined to the substance, with fixed volume and take the shape of the container

Gas

State of matter where particles are separated, with no fixed volume or shape

Phase

State of matter

Temperature

Measure of the average random kinetic energy of the particles

Absolute temperature

Temperature on a scale to show molecular motion

Absolute zero

Temperature at which all particle motion stops

Internal energy

Sum of the random kinetic energy and potential energy of the particles

Specific heat capacity

Amount of energy needed to raise the temperature of 1 kg of a substance by 1 K

Phase change

Melting, boiling, freezing, condensing,subliming

Specific latent heat

Amount of energy needed to change the state of 1 kg of a substance at a fixed temperature

Calorimetry

Method for measuring energy changes using temperature changes of materials

Method of mixtures

Method for measuring thermal quantiites using the rapid transfer of energy

Fusion

Change of state between solid and iquid

Vaporization

Change of state between liquid and gas

Pressure

Force per unit area exerted on a surface

Ideal gas law

pV=nRT

Kinetic model of an ideal gas

Particles are small, not interacting and are in constant motion

Mole

Amount of matter with the same number of particles as 12g of C12

Avogadro's constant

The number of particles in 1 mole of a substance

Real gas

Gas that may not obey the ideal gas law, especially at low temperature and high pressure

Boltzman distribution

Pattern shown in a histigram to show the range and frequency of particle speeds in a sample

Boltzman constant

Constant for relating temperature to mean kinetic energy of individual particles.

Power

The amount of energy transferred per unit time

Black-body radiation

The radiation from a theoretical 'perfect' black-body emitter which only depends on the temperature of the emitting surface

Albedo

The fraction of the radiation received by a planet that is reflected back into space = total scattered power/total incident power

Sankey diagrams

Energy diagram where the width of each arrow is proportional to the amount of energy in its section

Intensity

Power per unit area that is received by the object (Wm^-2)

Stefan-Boltzmann Law

the amount of energy per second radiated by a body depends on its surface area and the absolute temperature of the surface (P=econstantA*T^4)

Emissivity

a measure of how effectively a body radiates (e=useful power/input power, [0,1])

Conduction

Thermal energy is transferred along a substance without any overall movement of the substance --> process by which kE is passed from molecule to molecule

Convection

Only possible in fluids (liquids or gases): thermal energy moves between 2 points because of a bulk movement of matter

Radiation

The transfer of thermal energy without matter by radiating EM waves (all objects above 0K radiate EM waves)

Evaporation

Faster moving molecules leaving the surface of a liquid that is below boiling point. Causes cooling.

Solar constant

The amount of solar energy that falls per second on an area 1m^2 above the Earth's atmosphere that is at right angles to the Sun's rays = The amount of power that arrives from the Sun

Greenhouse effect

Warming of the upper atmosphere and surface of the Earth due to greenhouse gases,

Greenhouse gases

Gases in atmosphere that absorb and re-radiate infra-red radiation in all directions

Wien's displacement law

Most of the energy is radiated at a specific wavelength that is determined by the temperature of the body