1. Volume: Most substances expand when heated and contract when cooled. This is due to the increased kinetic energy of the molecules, causing them to move further apart. This property is crucial in applications like thermometers and the design of structures that need to withstand temperature changes.
2. Density: Density is defined as mass per unit volume. Since volume changes with temperature, density will also change. Substances generally become less dense when heated as their volume increases. This is why hot air rises, and why hot water floats on top of cold water.
