What is the periodic table used for in biology and physics? What is the table used for finding in the subject?

I need to know how is the periodic table is used for in Biology and Physics? What information can you gather using the table and use it in biology/physics? Also, what industries use the periodic table...some links to information on the industries would help.What is the periodic table used for in biology and physics? What is the table used for finding in the subject?
the periodic table can be used to figure out compounds, like H2O which is water. it also shows many other characteristics of the elements in the periodic table....hopefully this is the periodic table that im thinking it is....lol



http://www.webelements.com/



http://periodictable.com/



http://periodic.lanl.gov/default.htm