Radium

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Radium,  88Ra
Radium226.jpg
General properties
Appearancesillery white metallic
Mass nummer226 (most stable isotope)
Radium in the periodic cairt
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gowd Mercur (element) Thallium Leid (element) Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium
Ba

Ra

(Ubn)
franciumradiumactinium
Atomic nummer (Z)88
Groupgroup 2 (alkaline yird metals)
Periodperiod 7
Element category  alkaline yird metal
Blocks-block
Electron confeeguration[Rn] 7s2
Electrons per shell
2, 8, 18, 32, 18, 8, 2
Pheesical properties
Phase (at STP)solit
Meltin pynt1233 K ​(960 °C, ​1760 °F) (disputed)
Bylin pynt2010 K ​(1737 °C, ​3159 °F)
Density (near r.t.)5.5 g/cm3
Heat o fusion8.5 kJ/mol
Heat o vapourisation113 kJ/mol
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 819 906 1037 1209 1446 1799
Atomic properties
Oxidation states2 ​(expectit tae hae a strangly basic oxide)
ElectronegativityPauling scale: 0.9
Ionisation energies
  • 1st: 509.3 kJ/mol
  • 2nd: 979.0 kJ/mol
Covalent radius221±2 pm
Van der Waals radius283 pm
Coloyr lines in a spectral range
Spectral lines o Radium
Miscellanea
Creestal structur ​body-centred cubic
[[File:body-centred cubic|50px|alt=Body-centred cubic creestal structur for radium|Body-centred cubic creestal structur for radium]]
Thermal conductivity18.6 W/(m·K)
Electrical resistivity1 µΩ·m (at 20 °C)
Magnetic orderinnonmagnetic
CAS Nummer7440-14-4
History
DiskiveryPierre Curie an Marie Curie (1898)
First isolationMarie Curie (1910)
Main isotopes o radium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
223Ra trace 11.43 d α 219Rn
224Ra trace 3.6319 d α 220Rn
225Ra trace 14.9 d β 225Ac
226Ra trace 1600 y α 222Rn
228Ra trace 5.75 y β 228Ac
| references | in Wikidata

Radium is a chemical element wi seembol Ra an atomic nummer 88.