General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles


Name Radium Symbol Ra
atomic number 88 Atomic weight 226.0254
Density @ 293 K 5 g/cm3 Atomic volume 45.20 cm3/mol
Group Alkali Earth discovered 1898


state (s, l, g) s
melting point 973.2 K boiling point 1973 K
Heat of fusion ? Heat of vaporization ?
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1st ionization energy 509.4 kJ/mole electronegativity 0.9
2nd ionization energy 979.1 kJ/mole electron affinity kJ/mole
3rd ionization energy kJ/mole Specific heat 0.12 J/gK
heat atomization 159 kJ/mole atoms

Oxidation & Electrons

Shells 2,8,18,32,18,8,2 electron configuration [Rn] 7s2
minimum oxidation number 0 maximum oxidation number 2
min. common oxidation no. 0 max. common oxidation no. 2
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Appearance & Characteristics

structure bcc: body-centered cubic color white
uses neutron source toxicity
hardness mohs characteristics Radioactive, luminescent


reaction with air vigorous, = RaO2, Ra3N2 reaction with 6M HCl
reaction with 6M HCl reaction with 15M HNO3
reaction with 6M NaOH
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Other Forms

number of isotopes 4 hydride(s)
oxide(s) chloride(s) RaCl2


ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius pm ionic radius (1+ ion) pm
ionic radius (2+ ion) 162 pm ionic radius (3+ ion) pm
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thermal conductivity 18.6 J/m-sec-deg electrical conductivity 1/mohm-cm
polarizability 38.3 A^3


source pitchblende(U-238 decay) rel. abund. solar system log
abundance earth's crust -6 log cost, pure $/100g
cost, bulk $/100g
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World Wide Web presentation of Chemicool Periodic Table is © Copyright 1996-99 by David D. Hsu. Some data were provided by and used with the permission of JCE Software and is owned and copyright by the Division of Chemical Education, Inc. Additional data were provided by Perkin-Elmer through Peter Lykos of IIT. The information may not be redistributed without the permission of David Hsu or JCE Software.