After a quick cookie and drink break in the dining hall, they moved onto Chemistry. In the lab they investigated a white powder that had been found at the scene (sugar?), some rocks & soil found near where the doughnut was last seen and a note left by the thief. In order to analyse any possible fingerprints, the children needed to use a method called sublimation to reveal any hidden evidence – they did this by putting a sample of the note into a container with iodine and then warmed it up in their hands to reveal the fingerprints, they then compared these to samples taken from the suspects. Moving onto the white powder, they first used Bunsen burners to try to identify the substance and then compared it to chemical evidence found on the suspects. In order to help them confirm the identification of the powder, they also tested it against the pH scale using distilled water and universal indicator and comparing it against the pH Scale. Finally, they used acid to test the rocks to see if there was any reaction – they discovered that limestone fizzes when it comes into contact with acid and this helped them narrow down in which house the culprit might live.
A delicious lunch was served in the dining hall before we gathered in the quad to watch the famous Band Parade and the resident students march into lunch.
Our final lesson of the day was in the Physics lab. Some Year 9 students helped the children to investigate some glass shards using glycerol and refraction techniques to see if the glass ‘disappeared’ when submerged. After a demonstration on how UV light is used to highlight seemingly invisible substances, they moved on to chromatography to try and find out whose pen might have been used to write the note left by the culprit. Using a special chromatography paper with samples of ink (the solute), they dipped it into liquid (the solvent) and watched to see the ink travel up the paper and then compared it to the crime scene sample.
A final trip to the dining hall for our very own doughnuts and it was time to head home. It was an exciting and fascinating day for Amara, Caleb and Alfie and a wonderful opportunity for them to learn something new!