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Reactive Elements



A Year 10 science lesson on exploring the reactive properties of sodium and potassium is examined in this chemistry video full of ideas to help teachers with their lesson planning.

Assistant Headteacher Nigel Regan explains how his planning includes a risk assessment as he is working with open flames and reactive metals which fizz when introduced to water. He must also be aware of how and when he will be moving his GCSE pupils around the class.

Nigel, who has extensive experience of conducting classroom experiments, sets up his equipment with tall safety screens positioned close to the water trough to significantly reduce the chance of a piece of sodium or potassium flying over a screen. By using only very small pieces of metal and seating his pupils at a good distance from the experiment, he further reduces the risk of an accident to pupils.

For the lesson starter he recaps on what his students can recall about the periodic table. He then conducts the practical experiments to compare and contrast the reactions of sodium and potassium.

For the plenary, Nigel asks his pupils to consider why sodium is less reactive than potassium and the connection that this might have with the position of their respective electrons.

After the lesson, he considers how its delivery might be improved and gives a tip for other teachers to follow when planning their science lessons.

Published : Aug 2010

04 mins


Lesson Planning


Secondary Teacher


Secondary Science



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