Floating and sinking

We investigated floating and sinking in 2nd class today. We tested a number of items including coins, spoons, parers and rulers. Some boys were surprised to find that the heavier items didn't always sink. It was also interesting to see what happened to an orange before and after it was peeled - we thought that because the orange would be lighter with the peel removed it would float however this wasn't the case. This is because the peel is less dense than the orange so it allows the orange to float when it is on but the orange sinks without it - like a life jacket!