Radium

88
Ra
Gruppe
2
Periode
7
Blok
s
Protons
Electrons
Neutrons
88
88
138
General Properties
Atomnummer
88
Atommasse
[226]
Mass Number
226
Kategori
Jordalkalimetaller
Farve
Silver
Radioactive
Ja
From the Latin word radius meaning ray
Krystalstruktur
Rumcentreret Kubisk
History
Radium was discovered by Marie Curie and Pierre Curie in 1898.

They extracted the radium compound from a uraninite sample.

Radium was isolated in its metallic state by Marie Curie and André-Louis Debierne in 1910 through the electrolysis of radium chloride by using a mercury cathode and distilling in an atmosphere of hydrogen gas.
Elektroner i hver skal
2, 8, 18, 32, 18, 8, 2
Elektronkonfiguration
[Rn] 7s2
Ra
Radium imparts a carmine red color to a flame
Physical Properties
Tilstandsform
Fast stof
Massefylde
5,5 g/cm3
Smeltepunkt
973,15 K | 700 °C | 1292 °F
Kogepunkt
2010,15 K | 1737 °C | 3158,6 °F
Smeltevarme
8 kJ/mol
Fordampningsvarme
125 kJ/mol
Varmefylde
-
Abundance in Earth's crust
9,9×10-12%
Abundance in Universe
n/a
Pierre
Billede akkrediteringer: hp.ujf.cas.cz
Pierre and Marie Curie in the laboratory
CAS Number
7440-14-4
PubChem CID Number
6328144
Atomic Properties
Atomradius
-
Kovalent radius
221 pm
Elektronegativitet
0,9 (Paulings skala)
Ionization Potential
5,2784 eV
Atomic Volume
45,20 cm3/mol
Varmeledningsevne
0,186 W/cm·K
Oxidationstrin
2
Applications
Radium was formerly used in self-luminous paints for watches, nuclear panels, aircraft switches, clocks, and instrument dials.

Radium chloride was used in medicine to produce radon gas which in turn was used as a cancer treatment.

The isotope 223Ra is currently under investigation for use in medicine as a cancer treatment of bone metastasis.
Radium is highly radioactive and carcinogenic
Isotoper
Stable Isotopes
-
Unstable Isotopes
202Ra, 203Ra, 204Ra, 205Ra, 206Ra, 207Ra, 208Ra, 209Ra, 210Ra, 211Ra, 212Ra, 213Ra, 214Ra, 215Ra, 216Ra, 217Ra, 218Ra, 219Ra, 220Ra, 221Ra, 222Ra, 223Ra, 224Ra, 225Ra, 226Ra, 227Ra, 228Ra, 229Ra, 230Ra, 231Ra, 232Ra, 233Ra, 234Ra