I am a chem student and am in need of someones help. I am unable to find a simple explanation as to why samples can be separated into their components by chromatography. If someone could take a few minutes to give me a brief axplanation it would be greatly appreciated!!

obviously you have a computer that is connected to the internet. have you tried the search feature? give it another go.

Hi Tracy,
you want a simple explanation for something which is not so simple! Let me try it:

A mixture of compounts can be separated by moleculare size (A) or interaction with the stationary phase (B)!

(A) Gel Permeation Chromatography GPC, Size Exclusion Chromatography SEC are used to separate by molecular size. For a given pore size small molecules are going more often into the pore, larger molecules not. So larger molecules come out of the column faster than small molecules.
This technic is used for biomolecules and for polymers. Mobile phase could be water or organic solvent, or a mixture of both.

(B) Reversed Phase Chromatography RPC, Hydrophobic Interaction Chromatography HIC, Affinity Chromatography AFC, Ion Exchange Chromatography IEC (and others) are using some interaction between the stationary phase and the compounts. Some are more retarded by bonding to the surface chemistry than others. Dont forget that also size exclusion effects, and some other effects are involved in a chromatographic separation.
I hope this is helpful for you. If you need more detailed informations just have a look into some catalogs of HPLC column manufacturers.
Regards
Gerhard