the show we did in Bologna (Italy) was about 2 hours long and had a theme through out, like a story telling. We showed videos of the Zeppelin that caught fire in 1937 and use that one to talk about gases and inert gases vs explosive ones. We talked about the Space Shuttle Challenger disaster in 1986 and used that to show how rubber properties change with temperature (we had liquid nitrogen and a rubber tube). We also talk about separation of different molecules by TLC while all the time having experiments at the ready to show how these things work etc. There is a lot of Chemistry experiments that can be used and that are highly visual and catchy!