Advice for planning and delivering a Year 10 science lesson At Warden Park School in Sussex Assistant Head Nigel Regan plans an exciting lesson based on exploring the reactive properties of sodium and potassium. His planning has to take into account a risk assessment as he is working with open flames and reactive metals which fizz when introduced to water. He has to be aware of how and when he will be moving his pupils around the class. For his starter he recaps on the knowledge the students can recall about the periodic table, before moving onto to conducting the experiments to compare and contrast the reactions of sodium and potassium. In his plenary he asks his pupils to consider the reasons 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.