Chemicool

Ra

88

226.0254
Radium
General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles

General

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

States

state (s, l, g) s
melting point 973.2 K boiling point 1973 K
Heat of fusion ? Heat of vaporization ?
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Energies

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

Reactions

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

Radius

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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Conductivity

thermal conductivity 18.6 J/m-sec-deg electrical conductivity 1/mohm-cm
polarizability 38.3 A^3

Abundance

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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