Physics Narrative for 11-14
Here you can find out more about density
To appreciate the idea of density just imagine you can look deep inside a material. If the particles are packed closely together there is a lot of mass in a small volume.
If, on the other hand, there is a lot of space between the particles, the material will be less compact and will not be so dense. This relationship between the mass of an object and the volume it takes up is the key to appreciating density. In the real world, the mass of the particles themselves might also be different and this will influence the density of the material. Some materials, for example honeycomb, also have large spaces in their structure. This will tend to reduce their density.
Anyone who has moved boxes when setting up a new home will tell you that some boxes contain many more items, densely packed, than others. The box with all of the books in it (densely packed) is the one to avoid carrying! Delicate glassware will have lots of air between the items and is easier to handle.