Teaching the Halogens: Some Ideas

How do you teach about the halogens? I am in the middle of teaching about them and thought it was worth telling you how I introduce the topic. I do like this topic as it provides lots of opportunities to link together parts of the course. Firstly, I will start with some theory, things such as the fact that the halogens are diatomic and are the only group whose members exist as solids, liquids and gases at room temperature. This then leads into ...

Halogen reactions – a summary

Here is a great YouTube video that summarises the reactions of the halogens. As far as I can make out, all of the clips come from http://www.periodicvideos.com/ but the author of the video has combined a lot of these clips to put them together in one place. Some of the reactions that are shown are off syllabus but I still think it is worth showing to the students as they get a feel for the relative reactivity of the molecules. tk5xwS5bZMA

Astatine (At)

  Astatine comes after Iodine in group 7 of the periodic table. Mendeleev famously left a space for it when he put his periodic table together. The Guinness Book of World Records has called Astatine the rarest element on Earth. At any one time there is less than 25g of it present. It was first produced in 1940 at the University of California by Emilio Serge by bombarding Bismuth with Helium ions (He2+). The stalest isotope of Astatine   has a half life of ...