Density

Density is a measure of how tightly packed matter is in a given space, calculated by dividing an object's mass by its volume. Think of it this way: a bowling ball and a beach ball might be similar in size, but the bowling ball is much denser because it has more material squeezed into the same amount of space, which is why it sinks in water while the beach ball floats. Understanding density helps us predict whether objects will float or sink, and it's a key property that scientists use to identify materials and understand how they behave in the physical world.