Last week, students from the French Section visited the Chemistry lab Laboratory to see Sublimation in action as part of their study of States of Matter. Sublimation is when a solid turns directly into a gas without melting.

While very few substances sublime, one exciting one to observe is Iodine. Because it is toxic, the heating of shiny grey Iodine crystals must be carried out in the fume cupboard. As the grey crystals turn into a vibrant purple gas, the toxic fumes are removed by the fume cupboard. The students were excited to see large clouds of the purple Iodine gas. When poured onto a cold test tube, the gas quickly formed beautiful Iodine crystals once again. One other common substance that sublimes is Dry Ice. This is another name for solid carbon dioxide.

When you buy ice cream at the supermarket, you can get some Dry Ice to keep it cold as you go home. Dr. Suzuki showed the students what happens when you put Dry Ice in water. The students were then set ‘homework’ to do with their parents. Buy an ice cream and then repeat the experiment at home. It was great to see the young students in the laboratory and they hope to visit again later in the year.