Boron

element · ultra-hard · chemistry · materials

Element number 5. Boron is a chemical element with the symbol B, and it's the lightest member of its group on the periodic table. It has three valence electrons, which means it loves to pair up and form compounds with other elements.

Two different forms. Boron can look completely different depending on how it forms. As a crystal it's dark, shiny, and brittle, but when it's powdered up it becomes a soft brown powder, even though both are made of the exact same element.

Harder than diamond. When boron combines with carbon or nitrogen, it creates compounds so incredibly hard they're used to cut, grind, and polish other hard materials. Boron nitride and boron carbide are among the toughest substances on Earth.

In your laundry. A mineral called sodium borate, which contains boron, has been used for thousands of years to clean clothes and dishes. It's one of the reasons some detergents work so well at getting out tough stains.

Space-age material. Boron is so useful in modern technology that scientists use it in aerospace materials, electronics, and even as part of special glass that can handle extreme temperatures.