Describe how the periodic table differentiates between metals and nonmetals.

Most of the elements on the periodic table are metals...generally speaking...metals occur on the left side of the periodic table, and non-metals occur on the right side of the periodic table... 

...check out the periodic table locate at: http://www.elementsdatabase.com/ 
look at the second colored periodic table...take a look at the key for this table...notice that the non-metals are colored white or red...all other elements would therefore be metals...