Lesson C2.10 http://www.rsc.org/Education/Teachers/Resources/Alchemy/index2.htm
https://www.stem.org.uk/resources/elibrary/resource/27552/alchemy (download)
Lesson C2.12.2
http://science.howstuffworks.com/nanotechnology3.htm
https://www.bbc.co.uk/bitesize/guides/zpvfk2p/revision/2
