Name/Origin: Radium comes from the Latin word “radius” which means ray. It is called ray because it is a radioactive metal that emits alpha, beta, and gamma rays as it decays.It doesn’t have an extensive history  because it is a recently isolated and discovered element. It was  discovered only in the early 1900’s.


Symbol: Ra


Classification: alkaline earth metal




Physical Properties


Description: lustrous radioactive metal-Radium is a white lustrous metal that has cubic crystal structure, and relatively high melting and boiling point.


Crystal Structure: Cubic


Color: silver/white (lustrous)


Taste: unknown


Texture: unknown


Intensive properties:

Density @ 293 K: 5.0 g/cm3

Boiling Point: 1737.0 °C (2010.15  °K, 3158.6 °F)

Melting Point: 700.0 °C (973.15    °K, 1292.0 °F)




Chemical Properties:



 *Radium is intensely radioactive, and as it spontaneously decays, it releases energy in the form of alpha, beta, and gamma rays. As the nucleus of radium decays, radium atoms transform into atoms of new and different elements. The final product of radium decay is the element lead. In addition, radium’s gamma rays kill organisms. Gamma rays are the most dangerous because they have greatest penetrating power and will ionize the atoms on the flesh. This results in  severe damage to the cells.

*In the air, radium’s radiation  makes the gas molecules ionize, and then the air conducts electricity. In addition, as radium metal is exposed to air, it forms a black coating of nitride, which protects the element from further oxidation.

*Radium reacts with water to form hydroxides.

*Radium causes phosphorescent substances to glow brighter and the element itself exhibits luminescence.

*The temperature near radium is several degrees higher than its surroundings because of its release of rays and energy.

*Lastly, when it is put in a flame, it glows red carmine  color.






            Radium is a rare metal and its compound are primarily found in uranium ores. In a uranium ore, there is one part radium for every three parts uranium. The chief and richest sources of radium are carnotite sands from the Republic of Zaire and from pitchblende in West Canada, while some carnotite exists in Colorado. Radium extraction from uranium production residues is a difficult chemical process and makes radium extraction expensive.



Toxicity: Radium is very radioactive and thus very toxic. Because it is radioactive its nucleus decay emits harmful Gamma Rays. These rays are electromagnetic rays that travel at the speed of light, unaffected by magnetic fields and ionize when they hit the skin of a living organism. This ionization causes severe damage to the skin cells and has other dangerous side affects. Inhalation, injection, or body exposure to radium can cause cancer, anemia, and other disorders.


Isotopes: All 25 of radium’s isotopes are radioactive, react with oxygen and water, and exhibit luminescence. Radium-26 is the most common isotope in nature.


Isotope            Half Life

Ra-222            38.0 seconds

Ra-223            11.43 days

Ra-224            3.66 days

Ra-225            14.9 days

Ra-226            1600.0 years

Ra-228            5.76 years


Atomic Structure:

Atomic Number: 88

Atomic Mass: (226.0) amu  

Electron Configuration:   [Rn]7s˛

This determines which periodic family the element is in and its chemical and physical properties.



Number of Energy Levels: 7

First Energy Level: 2

 Second Energy Level: 8

Third Energy Level: 18

Fourth Energy Level: 32

Fifth Energy Level: 18

Sixth Energy Level: 8

Seventh Energy Level: 2


 Uses in compound form: treating cancer, luminescence in early watches, paints, and gamma ray source

            Watches- When radium was first discovered it was used in watch dials for self-luminescence because of its luminescent properties. These watches were widely used during the early fifties but were no longer manufactured because of radiums dangerous side effects.

           Paints- When radium is mixed with a phosphor, like zinc sulfide, the mixture is used to make luminous paints.



      Radiotherapy (Cancer therapy)- Radium’s radioactive properties are used for radiotherapy in cancer treatment. As Radium decays, it emits radon gas, which is sealed in minute tubes and used in treatment of cancer.  


Gamma Ray Source- It is an excellent gamma ray source because as its nucleus spontaneously decays it emits very concentrated quantities of gamma rays.

Historical Background:


Date of Discovery: 1898

Discoverer: Pierre and Marie Curie   


      Marie Sklodowska-Curie was a remarkable chemist and physicist, who coined the term “radioactivity" and discovered radium.  Radioactivity is the spontaneous decay of the atom’s nucleus while emitting particles and electromagnetic radiation. As the element decays, it becomes a new element. She and her husband discovered radioactive properties  from studying the intensely radioactive radium.

She was a woman of many firsts:

*First to win 2 Nobel Prizes-1st woman to win Nobel Prize in Physics

       [ Physics (1903) and Chemistry (1911)]

*First to use the term radioactivity

*1st female lecturer, professor, and head of Lab at   Sorbonne University in Paris (1906)

*Isolated pure radium

Ironically the very element that sparked her fame and career led to her death. She died from Leukemia, which is a consequence of aplastic anemia caused by exposure to radium






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