Simple & Giant covalent substances (Edexcel GCSE Chemistry & Combined Science)

This lesson explains the properties of typical covalent simple molecular compounds and introduces diamond and graphite as giant substances. The lesson PowerPoint and accompanying resource have been primarily designed to cover point 1.34 of the Edexcel GCSE Chemistry & Combined Science specifications but also links to points 1.35 - 1.37 where the structure and uses of the giant covalent substances are described.

The lesson begins with a quick recap task where students have to recognise a covalent bond from a description and fill the missing part. Moving forwards, they are introduced to the fact that covalent molecules can be simple or giant. They are then presented with a table showing some properties of covalent molecules and having to group them as simple or giant in the short space of time that the table remains displayed on the board. This task challenges their observational skills, something which will again be tested later in the lesson as they study the structure of graphite and diamond. Time is taken to ensure that key details such as the strong covalent bonds in both sets of molecules is understood and that it is the weak intermolecular forces which are actually responsible for the low melting and boiling points. The last part of the lesson introduces diamond and graphite as allotropes of carbon and students will briefly learn why one of these conducts electricity whilst the other doesn’t. If you want a lesson about these allotropes in more detail, then please look for “Diamond and Graphite”. Progress checks have been written into the lesson at regular intervals so that students are constantly assessing their understanding and so misconceptions are quickly identified.