What's My Property

What exactly can we tell about an unknown substance by it's properties. We already know that a substance is matter that’s made of one kind of atom or molecule, and that has specific properties and that some substances are elements, which means they can’t be broken down into other substances through physical changes or chemical reactions. We also know that we can group substances and elements by their properties like we found that all of the metal things from the bottom of my backpack were shiny and attracted to a magnet. So metals have high reflectivity and magnetivity. What else do we know about metals?