Thermal Physics Flashcards
What is room temperature
25 degrees Celsius
What is absolute zero
-273 Celsius or 0K
Describe the compressibility of a liquid
The liquid itself is not compressible, rather the air in between
What is evidence for the kinetic molecular model of matter
The random motion of particles in suspension. Ie. Brownian motion which can be described in terms of molecular bombardment
What is specific latent heat
The amount of energy required to change the state of 1kg of a material without changing its temperature
What is boiling point determined by
The atmospheric pressure
Describe the difference between boiling and evaporating
Boiling occurs only at boiling point, throughout the liquid and the rate is dependent on the heat supply
Evaporation occurs at the surface of the liquid,through a range of temperatures and the rate depends on humidity, surface area and air movement above the surface
Are pressure and volume inversely or directly proportionate
Inversely
What happens to the potential energy as particles move further apart
It increases
Consequences of thermal expansion (3)
Railway lines and cement and buildings buckle unless they have expansion joints.
Hot water pipes would break if they didn’t have an expansion joint in the form of a loop
Expansion in a pendulum during warm weather slows the clock (thus they have adjusting screws)
Application of thermal expansion
Bimetallic strips. Two strips of metal, often copper and iron. When heated copper expands more than iron causing the iron strip to bend with copper on the outside
Switches in electrical circuits
Distinguishing properties of solids (4)
Incompressible
Keep their shape
Cannot flow
High density
Distinguishing properties of liquids (4)
Incompressible
Take shape of bottom of container
Flow
High density
Distinguishing properties of gas
Compressible
Fill volume of container
Flow
Low density
Particle structure of solids in terms of arrangement, separation and motion of the particles
Vibrate around a fixed/central position and do not swap positions as there are strong forces between molecules. The particles are arranged in a lattice and there is minimal space between particles
Particle structure of liquid in terms of arrangement, separation and motion of the particles
Fluid shape (takes shape of container)
Particles are close together, so have a fixed volume and can only be compressed slightly
Particles are loosely packed together and irregularly arranged
Liquid particles can move randomly in any direction, provided the particles stay close to one another - they can vibrate and slide over each other
Particle structure of gas in terms of arrangement, separation and motion of the particles
Randomly arrangement, unrestricted by each other so have completely random motion in any and all directions .
Relationship between motion of particles and temperature
Average kinetic energy is related to temperature, meaning the higher the temperature, the more kinetic energy and the more, quicker movement of particles. Particles have the least movement at 0K / -273*C
Boyle’s law
Pressure and volume of a gas
The less volume the more collisions between the particles and the wall of the containers. When they collide they exert a force meaning more collisions = more force causing pressure to increase
PRESSURE OF GAS IS INVERSELY PROPORTIONAL TO VOLUME
Evidence for the kinetic particle model of matter
Random motion of particular in a suspension. This (brownian) motion seen in dust + pollen is explained in terms of random molecular bombardment, massive particles moved by light, fast moving molecules of air.