Chemistry:

American Chemical Society – hit “Education” tab          http://portal.acs.org/portal/acs/corg/content

http://www.chemguide.co.uk/index.html#top

http://www.101science.com/Chemistry.htm

http://chemistry.about.com/

http://www.chemistrydaily.com/chemistry/

http://chemistry2.csudh.edu/lecture_help/lechelp.html

http://antoine.frostburg.edu/chem/senese/101/index.shtml

http://chemical-safety.com/labsafety.htm

Nanotechnology:

http://www.cneu.psu.edu/

http://www.understandingnano.com/index.html

http://www.nanotech-now.com/

http://nanotechwire.com/

http://nanowerk.com/

http://nanularity.com/default.aspx

Calculator:

http://education.ti.com/studentzone/getahead/tutorials.html