The Periodic Table: how patterns in reactions can be predicted with reference to the periodic table
Practical activities which look at the reactions of different groups of elements are always exciting. This list provides some advice on carrying out some traditional demonstrations and ideas for practicals which which explore reactivity.
Visit the practical work page to access all resources and lists focussing on practical work in secondary science: www.nationalstemcentre.org.uk/practical
Demonstrating Chemistry: Exciting Elements
This excellent film from Teacher TV is exactly what teachers need to enable them to demonstrate the reactions of groups I and VII and show how reactivity can be predicted. It’s full of detailed information about how to carry out the reactions and there are safety tips and advice that will enable teachers to feel confident that they can repeat them in front of a class.
If you haven’t tackled these reactions before, try them out on your own or with a technician before trying them with a class present.
Reactions of other elements are covered too and, as this film covers material from both keystage 3 and 4 teachers should choose carefully the reactions they use with their own students.
A further film from teachers TV, this time designed for students, provides an excellent follow up to these demonstrations and is provided below.
The Periodic Table: Ferocious Elements *suitable for home teaching*
This film shows loads of dangerous reactions that students will love. It’s designed to complement the reactions of elements, particularly those in groups I and VII and it’s a perfect follow up to teacher demonstrations as in the resource above.
The film takes a tour around the periodic table and as well as consolidating the reactions teachers will have demonstrated it goes on to show reactions of the more dangerous elements that aren’t kept in school. It lasts about a quarter of an hour.
Tales From the Prep Room: Alkali Metals
This isn’t a standard school demonstration but it’s worth trying if you fancy something a bit different ,perhaps to make a fun end to a lesson on the alkali metals. In this film you’ll see how to light a match using small pieces of sodium or potassium by dropping water on to them. It’s probably a bit small scale for students to see clearly what is happening so use of a camera or visualiser to project the image onto a screen – just think carefully about where to put it so that it isn’t damaged by the reaction.
Reacting elements with oxygen
This well thought out series of demonstrations from the Royal Society of Chemistry enables students to think through the reactions of group I and II metals. It would be helpful to use it after students have seen the reactions of the alkali metals with water. Teachers will want to practise with the equipment if they haven’t used it before.
With the rather complicated set up there is a danger that students won’t be able to “see the wood from the trees” and so it is important to talk through the experiment carefully so that students can separate the production of oxygen from its reaction with the metal.
It would be sensible to record what they see as the demonstrations are carried out perhaps drawing up a table detailing the name of the group of the reactant, the vigour of the reaction, and the names of the product formed. Students could be encouraged to predict how vigorous reactions will be before they see them.