DNA; flame tests.

http://nobelprize.org/educational_games/medicine/dna/index.html

http://ghr.nlm.nih.gov/handbook/basics/dna

http://www.dna.gov/audiences/investigators/know/whatisdna

http://fajerpc.magnet.fsu.edu/Education/2010/Lectures/26_DNA_Transcription.htm

http://www.attotron.com/cybertory/analysis/trans.htm

http://www.pbs.org/wgbh/aso/tryit/dna/

flame tests

http://www.tracy.k12.ca.us/ths/tchrs/djrond/Labs/Labs.htm