ch2 density demos

fill in this form about the density demonstrations

http://spreadsheets.google.com/viewform?formkey=dGpMR2sxajdldm9NWFlsYTlOZ3R5Q0E6MQ

didn't see the demonstrations? Go to the sidebar 'videos' and watch the video. densitee demontrations*

want to see what other students said? not shared until day after above is due