Cách sử dụng
Density is a word used to describe how much stuff there is in a certain amount of space. For example, a brick is more dense than a pillow because it has more stuff (material) inside of it in the same amount of space. Scientists can use the word density to talk about how heavy a certain amount of a material is or how tightly packed molecules are in a liquid or gas. Density is important in many different areas of science and engineering, such as building houses or designing airplane wings.