A substitute science teacher was conducting a common introductory lab in the grade nine applied chemistry strand, identifying unknown chemicals (salt, baking soda, chalk, sodium nitrate, and sodium thiosulphate) in numbered containers using physical properties. Prior to the activity the teacher was very careful to go over all the safe ways to observe a chemical such as, don’t touch with your hands, don’t smell, and don’t taste. She even commented that two of the chemicals were toxic. Once the prelab talk was completed, the chemicals and safety equipment were distributed and the students began the experiment. After a period of time one of the students approached the teacher and asked if the chemical in jar three (the sodium thiosulphate) was sea salt because it looked like it, but didn’t taste salty.
Learning by Accident – Don’t Eat The Chemicals
Categories: General Interest