This site provides information on the periodic table that includes the groups, periods, valences, electron shells, and characteristic trends.

Question: What are the characteristic trends of the periodic table?

These interactive chemistry exercises allow the user to visualize atomic orbitals. The 3-D animations are very helpful to the beginning chemistry student. Select "Computer Graphics".

Question: What is the maximum number of electrons that may occupy the "s" and "p" orbitals?

Draw Bohr's model of a carbon atom on a piece of paper.

http://esg-www.mit.edu:8001/esgbio/lm/proteins/structure/structure.html

The levels of protein structure are discussed and nicely illustrated.

Question: What are the four structural levels of proteins?

http://www-medlib.med.utah.edu/NetBiochem/macromol.htm

This is an excellent introduction to carbohydrates, nucleic acids, and proteins.

Question: On a piece of paper, match the monomer unit with the appropriate macromolecule: