Sniffing out the science of smells

Ever opened a backpack you haven’t used all summer to be hit by a face-scrunchingly bad smell? The stench usually emanates from a forgotten item of food that has been slowly rotting at the bottom of the bag. But what are the chemical culprits behind these and other obnoxious odours? Read the article to find the answer to this and other questions such as: can chemists guess whether something is going to smell nasty or nice? And can you cover up a bad smell with a good one? Download the resource for 11–14 learners to observe the sublimation of air freshener and demonstrate this unusual change of state as the solid becomes a gas without passing through the liquid phase.