Pure metallic radium is brilliant
white when freshly prepared, but blackens on exposure to air, probably due to
formation of the nitride. It exhibits luminescence, as do its salts; it
decomposes in water and is somewhat more volatile than barium. Radium imparts a
carmine red colour to a flame.
Radium emits a, ß, and gamma rays and when mixed with beryllium produces neutrons. Inhalation, injection, or body exposure to radium can cause cancer and other body disorders. alkaline earth metal, white but tarnishes black upon exposure to air, luminesces, decomposes in water, emits radioactive radon gas, disintegrated radioactively until it reaches stable lead, radiological hazard, a, ß, and ? emitter, exposure to radium can cause cancer and other body disorders. Radium is over a million times more radioactive than the same mass of uranium.
•Name: Radium
•Symbol: Ra
•Atomic number: 88
•Atomic weight: [ 226 ]
•Standard state: solid at 298 K
•CAS Registry ID: 7440-14-4
•Group in periodic table: 2
•Group name: Alkaline earth metal
•Period in periodic table: 7
•Block in periodic table: s-block
•Color: silvery gray, metallic
•Classification: Metallic
Historical information
Origin of name is from the Latin word "radius" meaning "ray". Radium was discovered in 1898 by Marie and Pierre Curie in pitchblende (or uraninite) from North Bohemia. The element was isolated in 1911 by Mme. Curie and Debierne by the electrolysis of a solution of pure radium chloride, employing a mercury cathode. On distillation in an atmosphere of hydrogen this amalgam yielded the pure metal.
Physical properties
•Melting point: 973 [or 700 °C (1292 °F)] K
•Boiling point: 2010 [or 1737 °C (3159 °F)] K
•Density of solid: 5000 kg m-3
Orbital properties
•Ground state electron configuration: [Rn].7s2
•Shell structure: 2.8.18.32.18.8.2
•Term symbol: 1S0
•Pauling electronegativity: 0.9 (Pauling units)
• First ionisation energy: 509.3 kJ mol-1
• Second ionisation energy: 979.0 kJ mol-1
Isolation
All isotopes of radium are radioactive and there is only ever any need to make radium metal on very small scales for research purposes. Radium is extremely scarce but found in uranium ores such as pitchblende at slightly more than 1g in 10 tonnes of ore. It may be made on very small scale by the electrolysis of molten radium chloride, RaCl2. This was first done using a mercury cathode, which gave radium amalgam. The metal was obtained by distillation away from the amalgam.
cathode: Ra2+(l) + 2e- ? Ra
anode: Cl-(l) ? 1/2Cl2 (g) + e-
Radium emits a, ß, and gamma rays and when mixed with beryllium produces neutrons. Inhalation, injection, or body exposure to radium can cause cancer and other body disorders. alkaline earth metal, white but tarnishes black upon exposure to air, luminesces, decomposes in water, emits radioactive radon gas, disintegrated radioactively until it reaches stable lead, radiological hazard, a, ß, and ? emitter, exposure to radium can cause cancer and other body disorders. Radium is over a million times more radioactive than the same mass of uranium.
•Name: Radium
•Symbol: Ra
•Atomic number: 88
•Atomic weight: [ 226 ]
•Standard state: solid at 298 K
•CAS Registry ID: 7440-14-4
•Group in periodic table: 2
•Group name: Alkaline earth metal
•Period in periodic table: 7
•Block in periodic table: s-block
•Color: silvery gray, metallic
•Classification: Metallic
Historical information
Origin of name is from the Latin word "radius" meaning "ray". Radium was discovered in 1898 by Marie and Pierre Curie in pitchblende (or uraninite) from North Bohemia. The element was isolated in 1911 by Mme. Curie and Debierne by the electrolysis of a solution of pure radium chloride, employing a mercury cathode. On distillation in an atmosphere of hydrogen this amalgam yielded the pure metal.
Physical properties
•Melting point: 973 [or 700 °C (1292 °F)] K
•Boiling point: 2010 [or 1737 °C (3159 °F)] K
•Density of solid: 5000 kg m-3
Orbital properties
•Ground state electron configuration: [Rn].7s2
•Shell structure: 2.8.18.32.18.8.2
•Term symbol: 1S0
•Pauling electronegativity: 0.9 (Pauling units)
• First ionisation energy: 509.3 kJ mol-1
• Second ionisation energy: 979.0 kJ mol-1
Isolation
All isotopes of radium are radioactive and there is only ever any need to make radium metal on very small scales for research purposes. Radium is extremely scarce but found in uranium ores such as pitchblende at slightly more than 1g in 10 tonnes of ore. It may be made on very small scale by the electrolysis of molten radium chloride, RaCl2. This was first done using a mercury cathode, which gave radium amalgam. The metal was obtained by distillation away from the amalgam.
cathode: Ra2+(l) + 2e- ? Ra
anode: Cl-(l) ? 1/2Cl2 (g) + e-
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