Physics Kinetic Theory

Conduction

• A concept of I/GCSE physics, Conduction is the transfer of heat through solids,
• Conduction works best in metals
• Metals contain free electrons which gain energy when they gain heat, they are then able to pass kinetic energy along the metal.
• Metals are therefore good conductors • Other materials don’t contain free electrons.
• They are bad conductors but good insulators.
• Insulators keep heat in.

Convection

• Convection is heat transfer in liquids and gases (fluids)
• Convection can happen because as particles get warmer they become less dense and rise.
• The warmer particles are then at the top of the liquid/gas although the thing heating the liquid is at the bottom.
• The particles at the bottom rise as they are less dense and the colder particles fall.
• This is how the whole liquid/gas gets heated.

Radiation

• Radiation is the heat transfer that doesn’t require any particles
• All things give off Infrared radiation
• The warmer an object is the more radiation is given off
• Dark, matt surfaces are good emitters and absorbers of infrared radiation
• Light, shiny surfaces are good reflectors of radiation but poor emitters and absorbers.

Condensation and Evaporation

• Evaporation is when a liquid turns into a gas
• Particles have different energies in a liquid and therefore some escape and become 
• The particles left over  in the liquid have a lower average kinetic energy than before.
• The liquid cools down
• Condensation is when a gas turns into a liquid
• Particles in gases have different energies
• When a particle doesn’t have enough energy to be a gas it condenses and forms bonds with the other particles.
•  This creates energy.
• To increase the rate of these two methods you:
•  Increase the surface area
•  Increase the draught over the substance

References:

• http://s2.thingpic.com/images/uF/Qdg2n6H1CrNryjuhxHNi5DtL.jpeg
• https://images.squarespace-cdn.com/content/v1/5cdecce138275f0001d2fd9b/1559604198390-5A58FI1E7ZTXIOIMYPIW/Water+Cycle+Graphic.jpg?format=1000w

That's the end of the topic!

Drafted by Kin (Physics)