particle model of matter Flashcards
(20 cards)
what is density
measure of compactness of a substance
calc for density
mass / volume
describe solids
strong force of attraction, particles in fixed positions, have little energy so vibrate, have the highest density
describe liquids
weaker force of attraction so particles are close but move past each other, more energy than solids, less dense than solids
describe gas
no force of attraction, particles have the most energy, less dense than liquids
what is internal energy
the total energy that particles have in their kinetic and potential energy stores
what do the particles contain in a closed system
kinetic energy stores and potential energy stores
how do you increase the internal energy
heating transfers energy increasing internal energy
leads to change in temp or change in state
what happens if a substance is heated anougth
the particles will have enough energy in kinetic energy stores to break bonds
what is a change of state
a physical change
same number of particles just arranged differently
what happens to the internal energy when you melt or boil
increase internal energy but is used for breaking intermolecular bonds
what happens to the internal energy when you condense or frezze
bonds form which releases energy so internal energy decreases
what is specifc latent heat
amount of energy needed to change 1kg of it from one state to another without a change in temp
calc for specific latent heat
slh = energy / mass
how does temp increase speed
temp is related to the average energy in the kinetic energy stores so the higher the temp, higher the average energy
how do colliding particles create pressure and how you increase it
when collide they exert force and so presusre
faster particles and more collisions increase the net force and so pressure,
what increases the speed of colling particles
increasing temp
how does pressure dcrease
if temp is constant increasing the volume means particles spread
how does a change in pressure cause a change in volume
pressure of gases cause a net force outwards at right angles but there is also a force out side due to the pressure outside
change in pressure either causes container to compress or expand
how can doing work on a gas increase temp
transfer energy by applying a force then you do work
doing work will increase its internal energy and transfers the energy to the kinetic energy stores increasing temp
