In trying to make sense of the universe, scientists have classified everything that exists into two broad categories: matter and energy. Simply stated, matter can be thought of as “stuff” and energy is “the stuff that moves stuff.”
Matter is anything made of atoms and molecules; it has mass and takes up space. Even though matter can be found all over the Universe, you only find it in a few forms. We'll be learning about three types, or “states of matter”: solids, liquids and gases.
Matter can change from one state to another, which we call a “physical change.” Physical changes usually occur when heat (energy) is either added or taken away. A good example of a physical change is when an ice cube melts. It starts as a solid but when you add heat, it turns into a liquid. If you heat it up even more, it turns into a gas (water vapor). The neat thing about a physical change is that it can be reversed. Cool the water vapor and it turns into a liquid; cool it even more and it changes back to a solid.
Sounds simple, right? Well don't go to sleep yet because there's a lot more to learn in the world of science and every few days we'll have answers to burning questions like, “Is your bottled water really fresh?”
Monday, September 5th