Nothing in life is to be feared. It is only to be understood.
-Marie Curie
radium.
Radium, also known as Ra, atomic number 88. It is an almost pure white alkaline earth metal. When it readily oxidizes on exposure to air, it becomes black in color. Radium's isoptopes are all highly radioactive. The most stable isotope, radium-226, has a half life of 1601 years and decays luminescent and glows a faint blue. Radium chloride, a form of radium was discovered by Marie Curie in 1898. Marie and Pierre later extracted the radium compound from uraninite and later published the discovery at the French Academy of Sciences. Since its discovery, it has given names like radium A and radium C2 to several isoptopes of other elements that are decay products of radium-226. In nature, radium is found in uranium ores in trace amounts. Some amounts are as small as a seventh of a gram per ton of uraninite. Radium has health effects when it is incorporated into biochemical processes because of its radioactivity and chemical reactivity.
PHYSICAL CHARACTERISTICS.
Pure radium is a pure white, silvery solid metal. It has a melting point of 700 degree Celsius. This makes the melting point 1292 degrees in Fahrenheit! It gets hotter, with a boiling point of 1737 degrees Celsius this makes it boil at 3159 degrees in Fahrenheit. Radium also has a density of 5.5g/cm. All of these characteristics are extremely similar to barium. Since radium is so harmful due to the radioactivity, it is not as well studied as much as its more stable, closely related element: barium. The radium-barium density ratio is comparable to the radium-barium atomic mass ratio, since these elements have very similar body centered cubic structures.
Chemical characteristics.
Radium is the heaviest known alkaline earth metal. When exposed to air, radium reacts quickly with it, forming radium nitride. This reaction causes a blackening of the white metal. Most radium compounds, though not formed easily, are ionic salts and precipitates with barium, strontium, and other lead compounds. Compounds of radium, when burned, flame red-purple. Radium reacts violently with water forming radium hydroxide. Because of its geologically short half life and intense radioactivity, radium compounds are quite rare, occurring almost exclusively in uranium ores. Radium is 2.7 million times more radioactive than the same molar amount of natural uranium, due to its shorter half life. A sample of radium metal maintains itself at a higher temperature than its surroundings because of the radiation it emits.
History.
Radium, latin for ray, was discovered on December 21, 1898 in a uraninite sample. While studying the sample, the Curies removed uranium from it and found that the remaining material was still radioactive. So, they separated out a radioactive mixture which was mostly barium compounds. This gave a green flame when burned and crimson lines that had never been documented before. The name of radium was given to the new element they had just discovered due to its power of emitting energy in the form of rays. On February 4, 1936, radium became the first radioactive element to be made synthetically in the United States.
polonium.
Polonium is a chemical element with the symbol Po and atomic number 84. This element was also discovered by Marie Curie. Much like radium, this element is a rare and highly radioactive element with no stable isotopes. It was discovered in the same uranium ore samples that radium was found in. A few applications of polonium include heaters in space probes and sources of neutrons and alpha particles. Polonium is classified as a metalloid, but other sources say that due to its properties and the way it acts, it is a metal.
HISTORY.
Polonium was named after Marie Curie's native land of Poland. Since Poland was under Russian, German and Austro-Hungarian partition, and did not exist as an independent country, Curie hoped that naming the element after her native land would publicize its lack of independence. After removing uranium from a sample of uraninite, the compound was even more radioactive. This caused the Curies to search for additional radioactive elements in the sample. They soon separated out polonium in July 1898 and five months later, separated out radium. In the U.S., polonium was produced during WWII. It was a critical part of the nuclear weapon designs, which was a key ingredient of the bombs detonator.