Chapter 14- Thermal Physics Flashcards
What is heating?
Heating is the transfer of energy from a region of higher temperature to one at a lower temperature
What is thermal equilibrium?
A state in which there is no net flow of thermal energy between two systems.
What is the triple point?
A specific temperature and pressure where the three phases of matter can exist in thermal equilibrium.
Why is the Celsius scale not perfect and what scale do we use instead and explain it?
We can make water boil at a lower temperature than 100 degrees C, if we change pressure, therefore it is not perfect, so instead we use the absolute temperature scale, which uses 2 fixed points that never change. These 2 points are the triple point of pure water and absolute zero- which is the lowest possible temperature and minimum internal energy- (0K).
Triple point of water - 0.01 degrees C, 273.16K, 0.61 kPa
How do we convert from degrees C to Kelvin?
Temperature(Kelvin) = Temperature(degrees C) + 273.15
A substance undergoes a change in temperature of 15 degrees C. State the change in temperature in Kelvin.
A change of 1 degrees C is the same as a change of 1K.
15 degrees C change —> 15K change
What is the kinetic model ?
Describes how all substances are made up of atoms or molecules, which are arranged differently depending on the phase of the substance.
Describe the arrangement of solids liquids gases
In solids the atoms or molecules are regularly arranged and packed
closely together, with strong electrostatic forces of attraction between
them holding them in fixed positions, but they can vibrate and so have
kinetic energy (Figure 2).
In liquids the atoms or molecules are still very close together, but they
have more kinetic energy than in solids, and - unlike in solids - they
can change position and flow past each other.
In gases, the atoms or molecules have more kinetic energy again than
those in liquids, and they are much further apart. They are free to
move past each other as there are negligible electrostatic forces between
them, unless they collide with each other or the container walls. They
move randomly with different speeds in different directions.
What is Brownian motion?
The random motion of smoke particles in air.
Do all the chapter 14 questions In photos
How does Internal energy increase? Define internal energy
Internal energy is the sum of the randomly distributed kinetic and potential energies of atoms or molecules within the substance.
Increasing the temperature of a body, increases the KE of the molecule, and increases internal energy.
When a substance changes phase, the potential energy increases, increasing internal energy.
Describe an electrical experiment to determine the specific heat capacity of oil. And define specific heat capacity
Describe the electrical experiments for specific latent heat of fusion and vaporisation. Define specific latent heat, then latent heat of fusion and vaporisation.
