Once considered a semiprecious metal alongside gold and silver, aluminum pretty much languished in obscurity until the 19th century. How did the metal become so ubiquitous? See more »

We love it. We wear it glittering around our necks and sparkling at our ears, wrists and feet. We pass it down to our children and hoard it in secret stashes. Why is this precious metal so prized? See more »

Lead is one of the most maligned metals on the periodic table and for good reason. Lead poisoning is serious. But the beleaguered element isn't all bad, especially when it's protecting you from radiation. See more »

It begins with an unassuming "H" and ends in crazy elements that you've likely never heard of. But the periodic table, encapsulated on a mere sheet of paper, can be a scientist's best friend and a testament to our human drive to organize the world. See more »

Barium, a soft, silvery-white, metallic element of the alkaline-earth group, related to calcium. See more »

Copper, a reddish metallic element. It was one of the first metals to be made into tools. See more »

Fluorine, a chemical element. It is a pale yellow gas at ordinary temperatures. Fluorine is a corrosive substance and has a strong odor. See more »

Helium, a chemical element that is a colorless, odorless, and tasteless gas at most temperatures and pressures. See more »

Helium is the second lightest element on the Periodic Table. How is helium created? See more »

We need oxygen to live, so it seems to me that if we got more oxygen, we would be better off. Is it harmful to breathe 100-percent oxygen? What will happen? See more »