Atomic number:88

Group numbers:2

Period:7

Electronic configuration:[Rn] 7s²

Formal oxidation number:+2

Electronegativities:0.9

Atomic radius / pm:235

Relative atomic mass:[226]

 

Radium was discovered by Marie Sklodowska Curie and Perre Curie (FR) in 1898. The origin of the name comes from the Latin word radius meaning ray. It is a silvery-white radioactive metal that reacts with oxygen and water. It is highly radiotoxic and carcinogen by inhalation, ingestion, or exposure. Radium is found in uranium ores at 1 part per 3 million parts uranium. Used in treating cancer because of the gamma rays it gives off.

Density / g dm^-3:5000 (293 K)

Molar volume / cm³mol^-1:45.20 (est., 293 K)

Electrical resistivity / μΩcm:100 (20 °C)

Thermal conductivity / W m^-1K^-1:18.6

Melting point / °C:700

Boiling point / °C:1140

Heat of fusion / kJ mol^-1:7.15

Heat of vaporization / kJ mol^-1:136.7

Heat of atomization / kJ mol^-1:159

1st ionization energy / kJ mol^-1:509.29

2nd ionization energy / kJ mol^-1:979.06

3rd ionization energy / kJ mol^-1:-

in the atmosphere / ppm:-

in the Earth's crust / ppm:-

in the oceans / ppm:3E-11