Particle Theory

A matter is made up from particles that are to small to see. 

An atom is the smallest particle.  It can not be broken down anymore. It is the smallest recognisable part of an atom.

A molecule is a particle made up of 2 or more atoms chemically bonded together. 

An ion is an atom or group of atoms chemically bonded that have an electrical charge. 

Soilds:                            dfaffafdafdasfdasfadfdfGases:

shape  fixed  dfaffafdafdasfdasfadfdfaffafdafdasfdshape  spreads out to fill container 

volume  fixed dfaffafdafdasfdasfadfdfaffafdafdasf volume  not fixed (expands) 

compressability not compressible  dfaffafdafdasfd compressability compressible 

 Liquids:

shape  flows easily takes shape of container  

volume  fixed

compressability not compressible 

Diffusion is the spreading out of a substance It occurs in liquids and gases

It occurs because moving particles collide with each other and bouce around 

Diffuison can not occur in soilds because the atoms are fixed in place.

The rate of diffuison increases with temperature because the particles are moving faster.

Small light particles diffuse faster than large heavy particles

Diffusion is faster in gases than liquids.  

There are 92 stable elements 

They are arranged by their atomic number from smallest to largest. 

An element is a pure substance made up of one type of atom

A compound contains atoms of 2 or more different elements 

They are chemically bonded together

Compounds can only be separated chemically not physically.

A mixture contains 2 or more substances which are mixed together but not chemically bonded 

They can be physically seperated

Filtration     -  The residue (solid) is trapped in the filter paper, when the liquid or solution passes through.

Centriuge    -  Inside the centrifuge, test tubes get spun around so the solid gets flung to the bottom and collects there.

Evaporation  - The solution is heated to evaporate the solvent          leaving the solute behind.

Simple Distillation - The solution is heated until it boils. The vapour rises and enters the condenser.  It cools, condenses and is then sperate from the solute.