From silverware to skyscrapers, metals form the physical foundation of our society. We use them to create artificial joints, build computers, solve transportation needs, fill dental cavities, wire our cities, incarcerate our criminals and adorn our bodies. Yet how much do you really know about these all-purpose elements?
For example, did you realize that calcium was a metal? How about sodium? Or, for that matter, potassium or lithium? Then there are the metals that sound like science-fiction writers named them: praseodymium, gadolinium and ytterbium.
So what exactly is a metal?
Because metals make up about 75 percent of the periodic table of the elements, their characteristics are extremely varied. Yet a generally accepted definition is that a metal is an element (something that can't be broken down into other components) that exhibits a luster or shine, has a certain degree of ductility and malleability (which means it can be hammered or twisted into wires), and conducts heat and electricity [source: Moore].
But as we'll see, just like some notorious heavy metal guitarists, not all metals obey the rules.