topic 3 - particle model of matter Flashcards
what is the arrangement of particles in a solid?
- particles are very close together
- particles arranged in a regular pattern
- particles vibrate but do not move from place to place
what is the arrangement of particles in a liquid?
- particles close together
- particles not arranged in a regular pattern
- particles can move around each other
what is the arrangement of particles in gases?
- particles are very far apart
- particles are not arranged in any pattern
- in a gas, particles are moving very rapidly
what is the density of a material?
mass / volume
describe how to determine the densities of regular solid objects
- determine the mass using a balance
- to work out the volume of the cube, we use a ruler to measure the length of the side
- the volume equals the length of the side cubed
- put the numbers into the equation mass/volume
determine how to determine the densities of irregular solid objects?
- find the mass of the object using a balance
- fill a Eureka can with water
- place the object into the water. This will cause water to be displaced and flow out of the can through the spout
- measure the volume of water displaced. this volume is the same as the volume of the object
what is potential energy?
- intermolecular forces and chemical bonds
what is internal energy?
- the energy stored in a system by the particles
- the total kinetic energy and potential energy of all the particles that make up a system
what is condensation?
gas -> liquid
what is sublimation?
- when a solid turns directly to a gas
what is sublimation?
- when a solid turns directly to a gas
what occurs to the mass when a change of state takes place?
- mass is always conserved
what happens if we reverse the change of state?
- the material recovers its original properties
what is evaporation?
- when a liquid turns to a gas but only on the surface of a liquid
what is the specific heat capacity?
the amount of energy required to raise the temperature of 1kg of the substance by 1°C
what is the specific latent heat?
- the amount of energy required to change the state 1kg of the substance with no change in temperature
how many joules does it take to melt 1kg of ice?
334 000 J of energy
what is specific latent heat of fusion?
- the energy required to change 1kg of a substance from a solid to a liquid with no change in temperature
what is the specific latent heat of vaporisation?
- the energy required to change 1kg of a substance from a liquid to a vapour with no change in temperature
what is the equation to find the energy needed for a change of state?
mass x specific latent heat
E = m x L
what is the pressure of a gas determined by?
- the particles colliding with the walls of the container that the gas is held in
how do you increase the pressure of a gas?
- increase the number of collisions per second
- increase the energy of each collision
what is the low temperature of gas determined by?
- at low temperatures, particles have low kinetic energy
- there are fewer collisions per second
- these are lower-energy collisions
-> low pressure
what is the high temperature of gas determined by?
- at high temperatures, particles have higher kinetic energy
- there are more collisions per second
- these are higher energy collisions
->high pressure
what do particle collisions cause?
a force which acts at right angles to the walls of the gas container
what is the relationship between the pressure of a gas and the volume?
- inversely proportional
PV = constant
- this equation is only true if the temperature is kept constant
what is work?
- the transfer of energy by a force
what is the effect of applying force to gas?
- energy is transferred to the gas particles
- because the kinetic energy increases, the temperature of the gas increases
