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RADIUM

 

Properties

Pure metallic radium is dazzling white after it has been isolated, but as it is exposed to the 

air it turns black due to oxidation. Radium displays luminescence, emits a red  colour when 

it is exposed to a flame and decomposes when it is placed in water.  Radium is similar in 

its properties (except for its radioactivity) to the alkaline earths - calcium, strontium and 

barium. It comes from pitchblende an ore of uranium and is  separated from it by using 

similar methods to those of the Curies. Radium emits  alpha, beta, and gamma rays and 

when mixed with beryllium produces neutrons.  Inhalation, injection, or body exposure to 

radium can cause cancer and other body  disorders. It has four naturally occurring 

radioactive isotopes, but others can be  produced in the laboratory. Radium has a half-life 

of 1620 years and the product of its  disintegration is, radon, an inert gas disintegrated 

radioactively until it reaches stable  lead. Radium is over a million times more radioactive 

than the same mass of uranium.  Radiation from radium has a harmful effect upon living 

cells, and radium burns are  caused by over exposure to the rays. 
 

Symbol:                                       Ra
Atomic Number:                          88
Atomic Mass:                              226.025
Group:                                        2
Period:                                        7
Electron Structure:       1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 7s2
1st Ionisation Energy/kJ mol-1:   509.3
Melting Point/K:                         973
Boiling Point/K:                          1413
Atomic Radius/pm:                     223
Electronegativity:                        0.9
Number of Natural Isotopes:       4