Heat Flashcards
what are the properties of a solid?
strong intermolecular bonds
tight spacing, a regular arrangement and a rigid structure
vibrates in a fixed position
low KE, high PE
what are the properties of a liquid?
weak intermolecular bonds
more movement and vibration
can pass eachother
more KE then a solid, less PE
what are the properties of a gas?
large amounts of space
particles move randomly
no bonding
high KE, low PE
conduction key points
works best in solids
happens faster in a metal because there are delocalised electrons
gasses are good insulators
solids that trap gasses are the best insulators
conevection key points
warm water displaces cold water because it is less dense, vice versa
in a fridge:
- air near cooling element is warm but cools
- becomes less dense and sinks
condensation key points
energy is transferred from gas to surface, KE decreases and bonds form, PE increases
reduce condensation by warming the surface that it reaches
evaporation key points
particles with most energy rise
particles near surface have enough energy to break bonds and evaporate
what are the factors that affect evaporation?
heat - more particles have sufficient energy to break bonds
SA - more particles at surface
movement of air - area becomes saturated with particles, air moves particles from surface
why does an evaporating liquid cool?
highest energy particles evaporate
average KE of particles decreases
specific heat capacity
amount of energy required to change 1kg of a substance by 1°c
the unites a J/kg°c
