PARTICLE MODEL OF MATTER Flashcards
which 2 quantities do you need to measure to find the density of a solid or liquid
mass and volume
what happens to the particles in a substance if its temperature is increased
they move faster and the energy in their kinetic energy store increases
why are the changes of state physical changes
no new substances are produced and the substance will have the same properties as before if the change is reversed
why is the mass of a substance conserved when it changes state
the number of particles doesn’t change
what is the internal energy of a substance
the total kinetic energy and potential energy of all the particles in a substance
why does a graph showing the change in temp as a substance cools have a flat section when the substance is changing state
the energy transferred during a change in state causes a change in the internal energy of a substance
what is the name given to the energy transferred when a substance changes state
latent heat
what is the specific latent heat of a substance
the energy required to change the state of 1kg of that substance with no change to the temp
what is the specific latent heat of fusion a substance
the energy required to change 1kg of the substance from solid to liquid at its melting point without changing its temp
what is the specific latent heat of vaporisation of a substance
the energy required to change 1kg of a substance from liquid to vapour at its boiling point, without changing its temp
what property of a gas is related to the average kinetic energy of its particles
temperature
what causes the pressure of a gas on a surface
the force of the gas particles hitting the surface
2 reasons why the pressure of gas in a sealed container increases if its temp is increased
- the molecules move faster so they hit the surface with more force
- the number of impacts per second increases so the total force of the impacts increases
2 reasons why the temperature of a gas increases if its compressed quickly
- the force applied to compress the gas results in work being done
- the energy gained by the gas is not transferred quickly enough to the surroundings
why does the pressure of a fixed mass of gas decreases if the volume is increased and kept at constant
the distance the particles travel between each impact with a wall of the container is greater, so the number of impacts per second decreases, so the total force of impact decreases
