http://teacher.scholastic.com/dirt/index.htm

http://www.sciencebob.com/experiments/polymer.php

http://www.internet4classrooms.com/science_elem_general.htm

http://science.pppst.com/energy.html

http://www.bbc.co.uk/schools/ks2bitesize/science/materials/gases_liquids_solids/play.shtml