40 Fun Facts About Radium

What were the Radium Girls taught to do to keep their brushes fine-tipped?

Point them with their lips was the instruction, so each painter swallowed a little radium with every dial. Rags and rinsing were discouraged because they wasted time and paint.

Radium was first found in ore from Jáchymov, a town whose silver coins gave which currency its name?

The dollar takes its name from the Joachimsthaler, a silver coin struck in the town from the 1500s and shortened to thaler. The same mines later supplied the ore for the Curies' discovery.

Marie Curie's research papers, still contaminated with radium, are kept in boxes lined with which metal?

Lead blocks enough of the radiation to make the papers safe to store, but anyone who consults them must still wear protective clothing. Even her cookbooks are radioactive.

The human body stores swallowed radium in the bones because it mistakes radium for which essential mineral?

Calcium shares a column of the periodic table with radium, so the body handles the two alike. Once locked into bone, radium irradiates the marrow from the inside.

Radium decays directly into which radioactive gas, a leading cause of lung cancer among non-smokers?

Radon is what radium turns into when it decays, and it was first known as radium emanation. Being a gas, it enters the body far more easily than its solid parent.

Which other element, named after Marie Curie's homeland, did the Curies discover a few months before radium?

Polonium came first, in July 1898, and radium followed that December from the same ore. The Curies found both by chasing radiation too strong for the known elements to explain.

Which two-letter symbol stands for radium on the periodic table?

Ra is radium's symbol, a name it happens to share with the Egyptian sun god. The element sits at number 88 and is the heaviest metal in its column.

Why did Marie Curie earn almost nothing from the booming radium industry that her discovery created?

She never patented her process, choosing to leave it open so that other scientists could work with radium freely. Factories were soon selling the element at enormous prices.

In which city did Marie and Pierre Curie discover radium while working in a leaky converted shed?

Paris was where the Curies worked, in a former dissecting room that was poorly ventilated and not even waterproof. They announced radium to the French Academy of Sciences in December 1898.

Which part of the body famously rotted away in dial painters who swallowed radium paint?

The jaw was hit so often that doctors named the condition after it, and dentists were among the first to spot the pattern. Sockets left by pulled teeth simply refused to heal.

Radium is the heaviest member of which periodic table family, alongside magnesium and strontium?

Alkaline earth metals fill the second column of the table, and radium is the only one with no stable form at all. It behaves most like the member sitting directly above it.

Which element, which burns with a green flame, is so like radium that the Curies struggled to separate the two?

Barium forms salts almost identical to radium's, and the ore contained far more of it. The Curies split the pair by crystallising the mixture again and again, since the radium salt dissolves slightly less.

Which tar-coloured ore did Marie and Pierre Curie process by the tonne to extract a speck of radium?

Pitchblende holds so little radium that a ton typically yields about a seventh of a gram. The Curies worked with leftover ore from which another metal had already been taken.

Roughly how long does it take for half of a sample of radium's most stable isotope to decay?

1,600 years is the half-life of radium-226, which makes up nearly all natural radium. A half-life that short, by geological standards, is what makes the metal so fiercely radioactive.

Nearly all radium in nature is constantly renewed by the slow decay of which heavier element?

Uranium decays through a long chain of elements, and radium is one of the links. Any radium present when Earth formed vanished long ago, so every atom found today is freshly made.

Pure radium is a silvery-white metal, but which colour does its surface quickly turn in air?

Black is the colour of the coating that forms almost at once, thought to be radium nitride. That would mean the metal reacts with the nitrogen in air rather than the oxygen.

Which technique did Marie Curie and André-Louis Debierne use in 1910 to isolate pure radium metal for the first time?

Electrolysis of a radium chloride solution left the metal dissolved in a mercury electrode. Driving the mercury off in hydrogen gas then gave the first pure radium, twelve years after its discovery.

The alpha particles shot out by radium pick up electrons and become which gas, which can shatter radium crystals?

Helium builds up inside crystals of radium bromide as the particles settle into ordinary atoms. The trapped gas weakens the crystals until some crack or even explode.

What did Pierre Curie and Albert Laborde find that radium gives off continuously, an early clue to nuclear energy?

Heat pours out of radium without pause, enough to keep a sample warmer than the room around it. It was the first sign of the energy locked inside atoms.

Radium's name was built on radius, a word meaning ray or beam in which language?

Latin supplied the root because the new element gave off its energy in the form of rays. The same word gives geometry its term for the line from a circle's centre to its edge.

Which radium tonic, sold in tiny bottles as a cure-all in the 1920s, killed a wealthy American industrialist?

Radithor was simply radium dissolved in distilled water, and Eben Byers drank some 1,400 bottles of it. His death in 1932 ended the craze for radioactive medicines.

Eben Byers, who died after drinking some 1,400 bottles of radium tonic, was a US amateur champion in which sport?

Golf made Byers famous when he won the 1906 US Amateur. He began taking the tonic on a doctor's advice after a fall from a train berth, and kept on because it made him feel toned up.

Radium companies tried to dodge blame by claiming their dying dial painters really had which disease?

Syphilis was the diagnosis the firms pushed, since its stigma also smeared the women's reputations. Company chemists, meanwhile, handled radium with tongs, masks and screens.

The first Radium Girls to sue worked at a United States Radium Corporation plant in Orange, in which state?

New Jersey was home to the plant, where as many as 300 workers, mostly women, painted glowing dials. Five of them settled in 1928 for $10,000 each plus a yearly payment for life.

Which brand name did the United States Radium Corporation give its glow-in-the-dark radium paint?

Undark went on watches, compasses, locks and even fishing bait, and was sold as a kit for painting things at home. Rival firms sold near-identical paints under their own names.

Why do most radium watch dials made a century ago no longer glow in the dark?

The phosphor has worn out under decades of bombardment, while the radium beneath is almost as radioactive as the day it was painted. That is why a dark old dial should never be scraped or opened up.

Which less dangerous radioactive substance took over from radium on glowing watch dials by the 1970s?

Tritium gives off radiation too weak to pass through skin, which made for a far safer glow. Most watches now use paint that is not radioactive at all and simply recharges in the light.

Which conflict first created mass demand for radium paint, to light soldiers' watches and instrument dials?

World War I put glowing dials in the trenches, where striking a light to check the time could give away a position. The paint was marketed to ordinary shoppers once the fighting ended.

Tho-Radia, launched in 1930s France under the name of a Dr Alfred Curie, was best known as a radium-laced what?

Beauty cream was the flagship product, and the doctor on the label was no relation to the famous Curies. The radium left the brand in 1937, when new rules limited radioactive ingredients to prescriptions.

From the 1940s to the 1960s, US doctors pushed radium up children's noses to treat which problem?

Hearing loss and repeated ear infections were the targets of the treatment. Airmen and submarine crews were given it too, for ear damage caused by changes in pressure.

Marie Curie's second Nobel Prize, awarded in 1911 for discovering and isolating radium, was in which field?

Chemistry was the field, eight years after she shared the physics prize for research into radioactivity. No one else has won Nobel Prizes in two different sciences.

Which US president presented Marie Curie with a gift of radium at the White House in 1921?

Warren Harding handed over a single gram, paid for by a fund that journalist Marie Meloney set up after interviewing Curie. The scientist crossed the Atlantic to collect it in person.

Which French physicist burned his own skin by carrying a sample of radium in his vest pocket?

Henri Becquerel found his skin ulcerated after six hours with the sample in his pocket. He was the man who had discovered radioactivity in the first place, and shared a Nobel Prize with the Curies for it.

Pierre Curie strapped radium to which part of his own body for ten hours to study the wound it left?

His arm developed a lesion, and he reasoned that anything able to destroy healthy tissue might destroy tumours too. The idea grew into radium therapy for cancer.

The radium-223 drug Xofigo is approved to treat cancer of which gland once it has spread to the bones?

The prostate is where these tumours begin, and the drug follows them into the skeleton because the body carries radium straight to bone. Its alpha radiation has a very short range, so healthy tissue nearby is spared.

Which European country, refining ore from its Congo colony, dominated the global radium trade in the 1920s?

Belgium shipped ore from the Shinkolobwe mine to a refinery at Olen and came to control the market. Radium salts were selling for about $70,000 a gram around 1930.

Port Radium, a mining settlement on the shore of Great Bear Lake, lies in which country?

Canada's Northwest Territories gained the settlement after prospector Gilbert LaBine struck rich ore beside the lake in 1930. The remote camp even hosted a yearly dogsled race.

Early geneticists such as Thomas Hunt Morgan dosed which insects with radium, hoping to trigger mutations?

Fruit flies were also dosed with radium by Hermann Muller, a future Nobel winner, who soon switched to cheaper X-ray equipment for his mutation research.

Physicists have found that the nuclei of some radium isotopes are lopsided, shaped like which fruit?

A pear is the shape, with one end of the nucleus fatter than the other. The lopsidedness makes radium a promising tool in the hunt for physics beyond today's standard model.

Radium becomes a handy source of neutrons when it is mixed with which lightweight metal?

Beryllium gives off neutrons when the alpha particles from radium strike it. Sources built this way were still in use in the early 2000s, though other radioactive materials have largely taken over.