Radiation Flashcards
What objects give off infrared radiation
Everything emits and absorbs infrared radiation, the hotter the object the more infrared radiation it emits
What’s the best emitter and absorber
Dark matt surfaces
What’s the owes the emitter and absorber
Light shiny surfaces
Why are solar heating panels painted matt black
The heating panels have to absorb heat radiation as quickly as possible so they can have as much hot water as possible at a time. It’s the best absorber, better than anything else like white or silver
What are particles like in a solid
They vibrate but stay in the same place in a structured position. It’s very dense and will never flow
What are particles like in a liquid
Sure in no set pattern so are random and they flow very easily and have a lower density than a solid
What are particles like in a gas
They’re very random and are completely free. The density is very low and it flows a lot but you can’t see them moving, they’re very fun fast
What is infrared radiation?
It’s a type of electro magnetic radiation which involves waves rather than particles. This means it can pass through a vacuum of space
What metal is quick at conducting heat
Copper
What is conduction like in non metals
The particles that are heated first begin to vibrate more and collide with neighbouring particles, his passes on the heat energy until all particles are hot
Why are metals good conductors (3)
They have lots of atoms and lots of free electrons
The free electrons can also move around and vibrate passing on heat energy in collisions
The heat energy is now passed on by neighbouring particles vibrating along the metal and by free electrons
How is heat energy transferred in a fluid
The heated fluid particles gain energy so they move about more and spread out. The same number of particles now take up more space, so the fluid has become less dense
How does convection work
The warmer particles spread out so are less dense and will rise and the cooler particles move together so are more dense and will sink
What’s evaporation
When a liquid turns to a gas
What’s condensation
When a gas turns to a liquid
