Radium
Radium is an alkaline earth metal element denoted by the atomic symbol Ra. The atomic weight of its most stable isotope is 226, and its atomic number is 88. It is a brilliant, white metal that is radioactive. It has a melting point of 1292°F (700°C) and a boiling point of 2084°F (1140°C).
The discovery and eventual refining of radium marked the culmination of the scientific community's acute interest in radioactivity, which began with the discovery of uranium's radioactive properties by French physicist Henri Becquerel. Marie Curie, a young Polish student who often observed Becquerel's research, chose this new field as the subject of her doctoral dissertation--which she had begun about the time she married the physicist Pierre Curie. The Curies combined their efforts in order to find other elements that possessed radioactive properties.
They began by refining a large quantity of pitchblende, a waste ore commonly found around uranium mines and known to emit radiation. After less than a year, they had extracted a measurable amount of radioactive salt which they called polonium. Though this new element was one hundred times as potent as uranium, the Curies detected another radioactive ingredient in pitchblende; though present in very small amounts, evidence showed that this newest element was thousands of times more radioactive than anything previously discovered. They called this element radium.
In order to confirm the existence of radium, the Curies attempted to extract enough from pitchblende to show other scientists. This would be no small task as.035 oz. (1 g) of the element would require tons of raw pitchblende and years of refining. Marie and Pierre used virtually all of their savings to purchase nearly a ton of ore, and, working in a wooden shed, labored ceaselessly over the next four years to purify it. By 1902, poverty-stricken and exhausted, they had produced.0035 oz. (.01 g) of radium.
The Curies shared the 1903 Nobel Prize for physics with Henri Becquerel for their contributions to science. Marie Curie received a second Nobel Prize in 1911 for her discovery of polonium and radium. She is the only person to win two prizes in the sciences. Curie died of leukemia in 1934, the result of her prolonged exposure to radiation.
One of the most radioactive metals in nature, radium is highly dangerous and requires careful handling. Radium proved especially useful in the treatment of certain cancers. Used in luminous paint at one time, radium is frequently found on the dials of old watches. The use of radium in such products, however, has since been curtailed due to its hazardous nature. Radium continues to be used in physical research as a source for gamma rays.
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