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?

All About Alloys

There are some familiar metals that are actually mixtures of several different types of metals - they are called alloys (AL-oise). Here are a few you've probably heard of (and some that are likely new to you):

• Steel: mixture of iron and one or more other metals (there will be a separate post about steel later)
• Brass (copper and zinc): a shiny yellow metal that looks a little like gold
• Bronze (copper and tin): a dark gold to brown metal that gets darker in color as it ages
• Pewter (copper, tin, and lead): a dark gray metal used for bowls, flatware, jewelry and other decorative items
• Solder (lead and usually tin): an alloy that melts at a relatively low temperature; used to make electrical circuits
• Nitinol (nickel and titanium): this alloy remembers its original shape; used to make eyeglass frames
• Electrum (gold and silver): also known as white gold; used in jewelry
• Alnico (aluminum, nickel, and copper): used to make magnets
• Amalgam (silver, tin, copper, zinc, and mercury): a soft alloy that has been used to fill dental cavities
• Nichrome (nickel and chromium): an alloy that glows orange-red and gives off heat when an electrical current is passed through it; used in toasters and electric burners

Take a look around your house and see how many examples of alloys you can find!

Fun Facts 10

Just one more set of facts after this one!

• The radioactive element actinium (Ac, #89) really does glow in the dark!
• Darmstadtium (Ds, #110) actually has a nickname. In Germany, where it was discovered, the emergency telephone number is 110 (not 911, as in the U.S.). Since Ds is element #110, it is sometimes jokingly called policium.
• Sometimes people worry about getting too much sodium (Na, #11) in their diets. But some sodium is essential to good health, because it helps send signals through your nerves.
• Rubies get their beautiful red color from chromium (Cr, #24).
• Metal objects that are going to be used outdoors are often galvanized, or coated with zinc (Zn, #30), which does not rust.
• Promethium (Pm, #61) has been detected in the stars of the Andromeda galaxy.
• Many laundry bleaches contain chlorine (Cl, #17). These are the bleaches that cannot safely be used on colored fabrics.
• Scientists have found rocks that contain a lot of manganese (Mn, #25) on the ocean floor. No one knows how they formed!
• In the future, rubidium (Rb, #37) might be used to make a new type of battery.
• Terbium (Tb, #65) is one of four elements that are named after the small town of Ytterby, Sweden. In the 1800's, rocks from that area were found to contain four unknown elements - ytterbium, yttrium, erbium, and terbium.