Chapter 14 - Thermal physics Flashcards
Triple point?
The temp and pressure at which all three phases of matter can co-exist in thermal equilibrium
Phase?
Another word for the state of matter e.g. solid
Thermal equilibrium?
Condition in which there is no net transfer of thermal energy between two objects
0th law of thermodynamics namics?
If two objects A and B are separately in thermal equilibrium with object C, then A and B must also be in thermal equilibrium with each other (all same temp)
Celcius temp scale?
Temperature scale where 0 degrees celsius is the freezing point of pure water and 100 degrees Celsius is its boiling point
Absolute temp scale?
Temp scale with two fixed points as the minimum possible temp (0K) - absolute zero, and the triple point of water 273.16 K, making 1k-2k and 1 Degrees celsius-2 degrees Celsius the same size difference
What do the letters stand for in Q/E=mc(change in temp)?
Heat energy = mass x specific heat capacity x change in temperature
Specific heat capacity definition?
The amount of energy needed to heat 1kg of a substance by 1K or 1 degrees Celsius
What does the letters stand for in c=(change in E) / (mass x change in temp)?
Specific heat capacity = (change in thermal energy) divided by (the mass x the change in temp)
What are the units for the specific heat capacity?
J Kg^-1 K^-1
What does the letters stand for in E = m x L?
Thermal energy = mass x latent heat capacity
How do you do the mean root squared?
Square every individual piece of data, add them all up, divide by the total number of pieces of data and then square root it
Absolute zero?
Lowest attainable temperature, where the substance in question has minimum (but not zero thanks to quantum effects) internal energy
Kelvin?
The unit used for absolute temperature, the size of 1K-2K is the same as 1 degree C - 2 degrees C
What is the kinetic model?
A model which describes substances in terms of the arrangement and motion of the atoms or molecules that make up the substance
Brownian motion?
The erratic random movement of microscopic particles in a fluid, as a result of continuous bombardment from molecules of the surrounding medium
Internal energy?
Sum of the randomly distributed kinetic and potential energies of all the particles in a substance
Specific heat capacity?
The energy needed to raise the temp of 1kg of a substance by 1K, whilst the substance is in constant phase (e.g. remains as a liquid during this)
Method of mixtures?
Method of determining the specific heat capacity of a substance by mixing it or bringing it into contact with a fixed amount of a substance (at a diff temp) with known heat capacity and measuring the temp changes
Specific latent heat of vaporisation?
Energy needed to change the state of a fixed mass (1kg) of a substance from liquid to gas at constant temp (it is also the energy released by the opposite process)
Vaporisation?
The phase change of liquid to gas (evaporate)
Sublimation?
The phase change of solid to gas
Melting?
The phase change of solid to liquid
How do you change degrees Celsius to kelvin?
+ 273
What effects the density of a substance?
The size of the spacing between particles in the substance
Description of the structure of a solid?
Molecules regularly arranged and packed closely with strong electrostatic forces of attraction between them, holding them in position
Describe the structure of a liquid?
Molecules are fairly close together, with more KE so can change position and flow past each other
Describe the structure of a liquid?
Molecules have a lot of KE so are arranged much further apart with negligible electrostatic forces
