Chapter 14 - Thermal Physics Flashcards
Thermal Equilibrium
Where two bodies have the same temperature so there is no net flow of energy
Flow of energy
Net flow from a hotter object to a colder one until they both have the same temperature
0th law of thermodynamics
If 2 objects are each in thermal equilibrium with a third then all 3 must be in thermal equilibrium with each other
Triple point of water
0.01C and 0.61kPa, where water exists as all three phases at the same time
Kelvin
Has absolute 0 at 0 degrees with the same intervals as degrees celcius
Kelvin formula
T(K) = θ(°C) + 273
Solid arrangement
Particles regularly arranged and closely packed with strong electrostatic forces holding them in fixed positions, vibrate with kinetic energy
Liquid arrangement
Particles very close together but have more kinetic energy so can change position and flow past each other
Gas arrangement
More kinetic energy and are much further apart. They are free to move past each other and have negligible electrostatic forces between them unless they collide with each other or the container walls. Move randomly with different speeds and directions
Brownian Motion
The seemingly random movement of particles as they move linearly between collisions with other particles and the walls of the container
Internal Energy
The sum of the randomly distributed kinetic and potential energies of atoms or molecules within a substance
Internal energy at absolute 0
Not equal to 0 as there is an electrostatic potential energy
Internal energy changes
Increases as you heat a substance as the kinetic energy increases
Increases with changes from solid to liquid and liquid to gas as the electrostatic forces increase
Potential energy of each state
Gases: 0 potential energy
Liquid: Negative electrostatic potential energy
Solid: Large negative electrostatic potential energy
SHC definition
The energy required per unit mass to change the temperature of a substance by 1K
