50 Fun Facts About Metals

Which everyday metal was still a costly rarity in 1884, when it capped the Washington Monument?

Aluminum cost about as much as a precious metal when the monument's tip was cast. Two years later a new electrical process made it far easier to produce, and the price collapsed.

First-place medals at the Olympic Games must be made of at least 92.5 percent which metal?

Silver makes up nearly all of an Olympic champion's medal, which carries just six grams of plating in the metal it is named for. Solid versions were last awarded in 1912.

Which metal forms the thin skin of the Statue of Liberty, which was a shiny reddish-brown when new?

Copper sheets were hammered into shape for the statue, and within about twenty years the air had turned them green. That crust, called verdigris, now protects the metal beneath it.

Which metal, long used in thermometers and barometers, is the only one liquid at room temperature?

Mercury is also known as quicksilver for the way it runs and shines, and its symbol, Hg, comes from the Latin hydrargyrum. Many countries have banned it from thermometers because it is toxic.

Which soft, heavy metal, used for ancient Rome's water pipes, gave English the word plumbing?

Lead was plumbum to the Romans, whose pipes were made of it, and the same Latin word explains its chemical symbol, Pb.

Which metal, the one with the highest melting point, glows as the filament in old-style light bulbs?

Tungsten melts only at 3,422 degrees Celsius, so a thin wire of it can glow white-hot without failing. Its symbol, W, comes from wolfram, the name it goes by in much of Europe.

Which metal, the least dense of all, powers the rechargeable batteries in phones and electric cars?

Lithium is one of only three metals light enough to float on water, and it is so reactive that it has to be stored under oil or in a vacuum.

Which metal coats the James Webb Space Telescope's mirrors because it reflects infrared so well?

Gold forms only a thin film on Webb's 18 hexagonal mirror segments, which are made of a much lighter metal and sealed under a layer of glass.

Which metal, the most common element on Earth by mass, lets the hemoglobin in blood carry oxygen?

Iron forms much of Earth's inner and outer core, yet an adult's body holds only about four grams of it, mostly in the blood.

Which alloy, the favorite for cast statues, swells slightly as it sets to fill a mold's details?

Bronze was the hardest metal in common use for so long that a whole age of prehistory, the one after the Stone Age, carries its name.

Which strong, light metal clads Bilbao's Guggenheim Museum and is used in bone and dental implants?

Titanium has the highest strength-to-density ratio of any metallic element, and it is one of the metals the human body tolerates best.

Which metal, locked up in the world's limestone, is also the most abundant metal in the human body?

Calcium sits almost entirely in the skeleton, which holds roughly 99 percent of the body's supply. In pure form it is a silvery metal that reacts quickly with air.

Which metal coats galvanized steel against rust and forms the core of US pennies struck after 1982?

Zinc plating is called galvanization in honor of the Italian scientist Luigi Galvani, and protecting steel this way is the metal's biggest single use.

Which alloy, long used for doorknobs, kills many microbes on its surface within hours of contact?

Brass, the metal of trumpets and trombones, can kill microbes within minutes to hours of contact, even antibiotic-resistant bacteria such as MRSA.

Which metal, named in 1789 after a newly found planet, is the main fuel of nuclear power plants?

Uranium honors Uranus, which William Herschel had discovered only eight years before the German chemist Martin Klaproth identified the new element.

Which metal, soft enough to cut with a knife, gives many street lamps their yellow-orange glow?

Sodium lamps give light of almost a single yellow-orange color, which makes them highly efficient but leaves people unable to tell colors apart beneath them.

Which non-metal element, usually under two percent of the mix, gives steel its hardness?

Carbon hardens the metal in small doses, but go much beyond two percent and the result is no longer steel but a casting alloy that tends to be brittle.

Which light metal burns with a brilliant white glare and was the flash powder of early photography?

Magnesium is still packed into fireworks and marine flares for the same dazzling light, and even into trick birthday candles that relight themselves.

Which metal, vital to nerve signals and plentiful in bananas, has the chemical symbol K?

Potassium owes its K to kalium, a Latin-style name proposed soon after its discovery, while its English name comes from potash, the plant ashes it was first isolated from.

Which metal discovered by Marie and Pierre Curie was once painted on watch dials to make them glow?

Radium paint poisoned the factory workers who applied it, known as the Radium Girls, who had been told to point their brushes with their lips.

Which metal makes up most of pewter and gives a crackling 'cry' when a bar of it is bent?

Tin is also the thin coating on steel food cans, where its low toxicity makes it safe beside what we eat.

Which metal, making up at least a tenth of the mix, is what makes stainless steel stainless?

Chromium, the metal behind the shine of chrome car trim, forms an invisible film on the steel that blocks rust and can heal itself when scratched.

Which dense precious metal made up 90 percent of the cylinder that defined the kilogram until 2019?

Platinum resists tarnish and is more than 21 times as dense as water, so the cylinder kept in a vault near Paris was only about the size of a golf ball.

Which process uses heat and a reducing agent such as charcoal to extract a metal from its ore?

Smelting is more than melting: the reducing agent strips away the elements bound to the metal, driving them off as gas or waste and leaving the metal behind.

Which property, distinct from being hammered flat, lets a metal be drawn out into a long, thin wire?

Ductility is why metals can be pulled through dies into cables; a material that cracks or shatters under that stress cannot be shaped this way.

Which fusible alloy is melted to bond wires and components permanently onto printed circuit boards?

Solder works because it melts at a far lower temperature than the parts it joins; one classic electronics blend turns liquid at just 183 degrees Celsius.

Which metal sits at the center of every vitamin B12 molecule and tints glass a deep blue?

Cobalt takes its name from kobold, a goblin of German folklore: silver miners used the word for ores laced with arsenic that spoiled their smelting and made them ill.

Which metal, used in blue LEDs, has a melting point so low that a lump turns liquid in your hand?

Gallium melts at just under 30 degrees Celsius, and Dmitri Mendeleev predicted its existence and several of its properties in 1871, before anyone had found it.

Which soft, reactive family sits below hydrogen in the first column of the periodic table?

Alkali metals all react with water, the heavier ones more vigorously than the lighter, and they take their name from the strong alkalis they form when they do.

What name is given to the official mark stamped on precious-metal items to certify their purity?

Hallmark comes from Goldsmiths' Hall in London, the guild headquarters where an assay office was set up in 1478 to test and stamp precious wares.

Which Cornish inventor of a miners' safety lamp was first to isolate six metals using electricity?

Humphry Davy freed two of the metals in 1807 and four more the following year by splitting compounds apart with electric current.

Which Englishman patented an 1856 process that blew air through molten metal to make cheap steel?

Henry Bessemer's blast of air burned the impurities out of the molten metal, giving the world its first inexpensive way to mass-produce steel.

Which metal, named after a Scottish village, gives fireworks and road flares their bright red color?

Strontium was recognized as a new element in the 1790s precisely because of the crimson color it gave a flame, years before anyone isolated the metal itself.

Which metal's atoms have set the official length of a second since 1967, inside atomic clocks?

Cesium gives off microwaves at a rock-steady frequency, and exactly 9,192,631,770 cycles of that signal are what the world counts as one second.

Which brittle metal grows rainbow, stair-stepped crystals and is swallowed in pink stomach remedies?

Bismuth gets its rainbow sheen from a thin oxide film that splits light, and its staircase shape from crystal edges that grow faster than the middles.

Which metal names the strongest type of permanent magnet, found in hard drives and cordless tools?

Neodymium magnets were developed independently in 1984 by General Motors and the Japanese firm Sumitomo Special Metals, and they have replaced weaker types in many products.

Which slow weakening of metal under repeated stress cracked the fuselages of early Comet jetliners?

Fatigue was barely understood when the Comet entered service, and each pressurized flight worked on the airframe until two of the aircraft broke up in the air.

Which heat treatment hardens red-hot steel by plunging it suddenly into water or oil?

Quenching cools the steel too fast for its structure to relax, which hardens it but can leave it brittle, so the piece is often reheated gently afterward.

Which ore, named after a village in Provence, is the main source of the metal in kitchen foil?

Bauxite takes its name from Les Baux, where the French geologist Pierre Berthier found it in 1821, and it is also the main source of a second, far rarer metal.

The blade of a dagger buried with Tutankhamun was forged from metal that came from which source?

A meteorite is the only source that fits, because the blade is about 11 percent nickel, far more than in any comparable metal made from Earth's own ores before the 19th century.

Which bluish-white metal, used to tip fountain-pen nibs, is the densest of all stable elements?

Osmium weighs about 22.6 kilograms per liter, a whisker more than its nearest rival; the two are so close that each was once thought the densest.

A thin layer of clay rich in which rare metal points to the asteroid that killed the dinosaurs?

Iridium is far more abundant in space rocks than in Earth's crust, which led a team under Luis Alvarez to propose in 1980 that an impact had delivered it.

Which natural pale-yellow alloy was struck into the earliest known coins, in ancient Lydia?

Electrum came to the Lydians ready-mixed by nature from the Pactolus river, a blend of the two best-known precious metals in varying proportions.

Which shape-memory alloy, used in medical stents, springs back to its original form when warmed?

Nitinol is named for its two metals and for the Naval Ordnance Laboratory, where it emerged from a 1959 search for missile nose-cone materials.

Which mix of nitric and hydrochloric acids did alchemists prize because it dissolves noble metals?

Aqua regia means royal water in Latin, a name alchemists gave it because it dissolves gold, which neither of its two acids can do alone.

Which scarlet mineral, ground for the pigment vermilion, is the chief ore of quicksilver?

Cinnabar is found most notably at Almadén in Spain, and it typically forms in veins around volcanic activity and hot springs.

Which property, found in 1911 in a deeply chilled metal, means zero electrical resistance?

Superconductivity was discovered by the Dutch physicist Heike Kamerlingh Onnes, and coils that exploit it power the magnets of MRI scanners.

Which unit, a little over 31 grams, is the standard weight for pricing and trading precious metals?

Troy ounces probably take their name from Troyes, a French market town, and each is nearly a tenth heavier than the ounce used in a kitchen.

Which naturally magnetic mineral, hung so that it could turn, served as the first magnetic compass?

Lodestone means 'course stone' or 'leading stone' in Middle English, a sign of how much early navigators relied on it.

Which Middle Eastern city shares its name with the legendary 'watered' steel of old sword blades?

Damascus blades were forged from ingots of wootz steel imported from southern India, and their banded surface was likened to flowing water.