Density is a physical property that measures how closely packed together a substances particles are. It explains why some objects float while others sink. Here are some key points to help kids understand density:

• Definition: Density is a measure of how much mass there is in a particular space.

• Formula: The density of an object is found by dividing the mass of the object by its volume. Density = Mass divided by volume.

• Floating and sinking: Generally, the greater the density of an object, the heavier it feels. Solid substances are denser than their liquid and gas counterparts as the particles in a solid are much more closely packed together. Objects and liquids float on liquids of a higher density and sink through liquids of lower density.

• Hands-on activities: There are many fun and easy experiments that kids can do to learn about density, such as making a density jar or exploring what floats in water.

Overall, density is a measure of how tightly packed the particles in a substance are, and it helps explain why some objects float while others sink.