particle model of matter

What is the particle model of matter? (3)

• theory that attempts to explain the 3 states of matter

• states that all matter consists of many small particles that are always moving

• particles are small inelastic spheres

Use particle model of matter to explain how melting works (3)

• in solids, strong forces of attraction hold particles together so they can only vibrate

• as it is heated, particles gain more energy and vibrate faster

• eventually particles gain so much energy that they overcome the forces holding them together and the substance melts into liquid

Use particle model of matter to explain how condensation works (3)

• in gases the particles have enough energy to overcome attractive forces so they spread out randomly

• if temp is lowered they will no longer have enough energy to overcome so particles will move closer together until they condense into liquid

In words, describe what is meant by density

how much mass a substance has per unit of its volume

How would you find the density of an irregularly shaped object? (3)

• measure mass on balance

• use eureka can and measure volume of water displaced to find its volume

• use mass and volume measurements to calculate density

In words, what is specific latent heat?

energy required to change the state of 1kg of an object without a change in temp

Why does temperature remain constant as a substance is changing state?

energy is used to break forces of attraction rather than being transferred to the kinetic energy store of the particles

What is meant by specific latent heat of fusion?

when a substance changes from solid to liquid or liquid to solid

What is specific latent heat of vaporisation?

when a substance changes from liquid to gas or gas to liquid

What is the relationship between pressure and volume, given that temp remains constant?

inversely proportional (when one increases, other decreases)