Oh, Penguin...

What Is Matter?

Even in a ninth grade honors science class, I have found not that many people know what matter is. Matter is anything that has mass AND volume. Volume is the property of taking up space. Mass is harder to understand, Physicists will define it as anything that "affects the rate at which an object changes its motion when subjected to a force." However, it can also be defined as " The property of an object that determines how much gravitational attraction it exerts on other objects." When most people think of matter, they think of atoms. But atoms are for another day. So in short, matter is anything that has mass AND volume.
Source: The book Bite-Size Science by Robert Dinwiddie (I recommend it!)

I would love to see his reaction!