science - Thermal energy/conduction/convection/radiation Flashcards
what is temperature?
a measurement of the average energy of particles in a substance
Why does a liquid get hotter?
The particles gain more energy which makes them bounce off each other quicker
what is thermal equilibrium?
when a hot object transfers energy to a cooler object until they reach the same temperature
what does conduction mean?
Heat transferred through solids
what does convection mean?
Heat transferred through liquids and gasses
what does radiation mean?
Heat transferred through electromagnetic waves
what does high density mean
particles are packed together, not much space
what does low density mean
particles are spread out, some or a lot of space
what is a convection current?
1=the object is heated up
2=it expands and becomes more dense
3=warm particles are forced upwards
4=cold particles are pulled down by gravity
the cycle repeats.
conduction or convection? - particles bump into nearby particles and make them vibrate more
conduction
conduction or convection? - particles with a lot of thermal energy in a liquid or gas move and take the place of particles with less thermal energy
convection
conduction or convection? - happens in only liquids and gasses
convection
conduction or convection? - happens in solids only
conduction
does radiation need particles?
No unlike conduction and convection, radiation does not need particles therefor thermal energy transfer can also happen in space
how does Heat escape conduction through solids?
through walls, roof, floors, windows
How does heat escape convection through gasses?
through loft spaces, chimneys and air gaps in between the bricks
How does heat escape radiation from hot surfaces?
through radiators
How to prevent heat loss through conduction
walls - foam in captivities
floors - carpets to trap in air
roof - layers of roof insulation
How to prevent heat loss through convection
walls - foam in captivities
chimneys - block if ur not using it
attics - reduce loft space
How to prevent heat loss through radiation
radiators - put silver foil at the back
what is a catalyst
a substance that speeds up a reaction without changing it
