Steel Away!

One of the most common metals used in today's world is steel. Steel is mostly iron, but it also contains other elements. As we've already seen, this kind of metal mixture is called an alloy. Most steel contains carbon in addition to iron. Stainless steel also has some chromium, and it doesn't rust. Other types include elements such as molybdenum, vanadium, tungsten, nickel, silicon, manganese, or boron. Different types of steel are used for different purposes. Some are good at high temperatures; others are hard and good at cutting.

The next time you're in a hardware or home-improvement store, take a look at the tools. How many different kinds of steel can you find?

Fun Facts 4

Continuing with our cavalcade of fun facts:

• The skeletons of certain types of sponges and other sea creatures are made up of silicon (Si, #14) dioxide, or SiO2. SiO2 is also the main component of glass, sand, and many rocks.
• Adding molybdenum (Mo, #42) to steel makes the metal even stronger. "Moly steel" was developed in the early 1900's, but a Japanese sword made in 1330 contains a lot of molybdenum. No one know how this was done!
• Bohrium (Bh, #107) is named after the Danish physicist Niels Bohr, whose birthday is today, October 8! Tillykke med fødelsdagen, Niels! (Apologies to any Danish speakers out there if this isn't right). Bohr was the scientist who first thought of the "miniature solar system" picture of the atom. Scientists later realized that this picture wasn't exactly right, but it was still an important idea!
• Osmium (Os, #76) is the densest metal. A one-foot cube of osmium would weigh over 140 pounds - that's heavier than many adults!
• Gadolinium (Gd, #64) is one of the elements called "rare earths" (#57 - #70), but it really isn't terribly rare. In fact, there is more Gd on earth than tin!
• Europeans didn't "discover" the beautiful silvery metal platinum (Pt, #78) until the 1700's. However, the native people of the Americas knew about it long before that!
• If you've ever flown on a plane, you know that the flight attendants tell you about the oxygen (O, #8) masks that drop down from the ceiling in case of a problem. The plane doesn't actually have containers of this gas (that would be dangerous), but they do carry chemicals that make oxygen when they react. If there is a problem, the two chemicals are mixed very quickly, and you can have oxygen gas to breathe!
• People with high blood pressure sometimes use a salt substitute instead of regular salt. This fake salt is actually potassium (K, #19) chloride.
• The metal indium (In, #49) makes a crying sound when a piece of it is bent!
• Radioctive neptunium (Np, #93) is the heaviest element found on earth, but it's only here in very tiny, tiny amounts.