88 Ra (Radium)
Appearance: Soft, shiny, Silvery white metallic
Mass number: 226
Atomic weight: 226.0254 g/mol
Atomic number(Z): 88
Electrons: 88
Protons: 88
Neutrons: 138
Group: 2
Period: 7
Block: s
Element category: Alkaline earth metal
Electrons per shell: K2, L8, 18, M32, N18, O8, P2
Electron configuration: 1s22s22p63s23p63d104s24p64d105s25p64f145d106s26p67s2
Phase: Solid
Melting point: 973 K (700 oC)
Boiling point: 2010 K (1737 oC)
Density: 5.5 g/cm3
Molar volume: 0.000045 m3/mol
Thermal conductivity: 19 W/m∙K
Half Life: 5×1010
Lifetime: 7.3×1010
Decay mode: α decay
Neutron cross section (Barns): 20
Heat of fusion: 8.5 kJ/mol
Heat of vaporization: 113 kJ/mol
Oxidation states: 2
Ion charge: Ra2+
The ionization potential of an atom: 5.4
Electronegativity: 0.9
Valence: 2
Ionization energies: 1st: 509.3 kJ/mol 2nd: 979.0 kJ/mol
Atomic radius: 215 pm
Covalent radius: 221±2 pm
Vander Waals radius: 283 pm
Crystal structure: Body-centered cubic
Thermal conductivity: 18.6 W/(m∙K)
Electrical resistivity: 1 μΩ∙m
Electrical conductivity: 1000000 s/m
Electrical type: Conductor
Magnetic ordering: Nonmagnetic
CAS Number: 7440-14-4
Discovery: Pierre and Marie Curie (1898)
1st isolation: Marie Curie (1910)
Isotopes: 223Ra 224Ra 225Ra 226Ra 228Ra
Uses: It is used in luminous paints, Radium-223 is used to treat prostate cancer
Biological role: It is toxic due to its highly radioactivity
Natural abundance: It is Present in all Uranium ores. 1×10-10%(In Earth’s Crust), 1×10-15%(In Oceans), 1×10-13%(In Humans)
#radium
