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Element 88 - Radium (Ra) sound

From radius, or ray; discovered 1898 by Pierre and Marie Curie; sixth rarest of the elements. A mixture of radium bromide and zinc sulfide was used in luminous watch dials. The radium gives off dangerous radiation which causes the zinc sulfide to glow.

Properties

Atomic Number: 88
Atomic Weight: 226.0254
Electron Configuration (at ground state): 1s22s22p63s23p63d104s24p64d105s25p64f145d106s26p67s2
Oxidation States (Bold most stable): +2
Boiling Point (K): 1413
Melting Point (K): 973
Density (at 300K -- g/cm3): 5.0
Atomic Volume (at 300K -- cm3/mol) 45.2
Number of natural radioactive isotopes: 4
Mass Number (Bold naturally occurring) -- Half-Life -- Disintigration Type: 226 -- 1.6 x 103 years -- alpha particle emission
Atomic Radius (Å): 2.23
First Ionization Potential (V): 5.279
Electronegativity (Pauling's): 0.89
Specific Heat Capacity (at 300K -- J g-1 K-1): 0.094
Heat of Vaporization (kJ/mol): 136.82
Heat of Fusion (kJ/mol): 8.37
Electrical Conductivity (at 293K for polycrystalline material -- 106 (ohms)-1 cm-1): 1.0
Thermal Conductivity (at 300K -- W m-1 K-1): 18.6
Crystal Structure: Cubic, body centered
Acid-Base Properties: Very basic