P6 particles Flashcards
what are the properties of particles in a solid? (how are they arranged)
particles are very close together
arranged in a regular pattern
particles vibrate but do not move
what is the arrangement of particles in a liquid?
particles are close together
not arranged in a regular pattern
particles can move around each other
what is the arrangement of particles in a gas?
particles are very far apart
not arranged in any pattern
moving very rapidly
what is density?
the mass of an object for a given volume
what is the formula which links density mass and volume?
density = mass / volume
what is the density pattern for solids?
they usually have a very high density
the particles are packed closely together so they have a lot of mass for their volume
what is the density pattern for liquids?
they are usually high density
the particles are close together so they have a lot of mass for their volume
what is the density pattern for gases?
they have a low density
the particles are far apart so gases have a small mass for their volume
what is the difference between a regular and an irregularly shaped object?
regular objects have dimensions which are easy to measure
irregular objects have dimensions which cannot be easily measured
how can the mass of an object be determined?
using a balance
how do you work out the volume of a regularly shaped object?
measure the length width and depth
multiply them together
how do you determine the volume of an irregularly shaped object?
fill a eureka can with water up to the spout
place the object into the can. this causes the water to be displaced and flow out of the spout
measure the volume of water displaced. this is equal to the volume of the object
what gives particles potential energy?
intermolecular forces and chemical bonds
what is internal energy of particles?
the energy stored in a system by particles
it includes the total kinetic and potential energy of all the particles that make up a system
what happens when you heat particles?
their internal energy store increases.
this can cause them to change state
what happens when you cool particles?
the amount of internal energy decreases
this can cause them to change state
what is sublimation?
when a solid turns directly to a gas
what happens to mass when changes of state take place?
mass is always conserved. particles are not added or taken away
what type of change is a change of state?
a physical change not a chemical one
if the change is reversed, the material recovers its original properties
what is evaporation?
when a liquid turns to a gas but only on the surface of the liquid
only particles on the surface have enough energy to change to a gas
what is specific heat capacity?
the amount of energy needed to raise the temperature of 1 kg of a substance by 1 degree
what does it mean if a material stores a lot of energy?
they need to gain lots of energy to increase the temperature and transfer lots of energy when they cool down
what is happening when the line is horizontal on a heating/cooling graph?
the substance is changing state
the energy is being used to weaken or break the forces of attraction between the particles
what happens when a substance changes state?
energy is being put into the substance when it is being heated up. this breaks the forces of attraction between the molecules allowing the substance to chance state
