Year 10 Density experiment

I filled the ice tray with water and weighed it. It came out at 159 grams.

 Then I put it into the freezer overnight. When it came out, it was still 159 grams.

 But if you compare the picture below with the the picture of the water in the tray, you'll notice that the ice is taking up more space. In the freezing process, the ice has expanded and has increased its volume.

Both the water and ice have the same mass, so you can't say that water is heavier than ice. However, because ice has a bigger volume, we say that ice has a LOWER DENSITY.
You calculate density by doing density = mass/volume.
Density is measured in grams per cubic centimetre      or      kilograms per cubic metre.