Atomic number:62

Group numbers:3

Period:6

Electronic configuration:[Xe] 4f⁶ 6s²

Formal oxidation number:+2 +3

Electronegativities:1.17

Atomic radius / pm:180.4

Relative atomic mass:150.36 ± 0.02

 

Samarium was discovered by Paul-Émile Lecoq de Boisbaudran (FR) in 1879. Named after the mineral samarskite. It is a silvery rare earth metal that is stable in dry air but reacts with water. Oxide coating forms on surfaces exposed to moist air and the metal ignites and burns readily. Samarium is found with other rare earths in monazite sand. It is used in the electronics and ceramics industries. It is easily magnetized and very difficult to demagnetise. This suggests important future applications in solid-state and superconductor technologies.

Density / g dm^-3:7520 (293 K)

Molar volume / cm³mol^-1:19.99 (293 K)

Electrical resistivity / μΩcm:88 (20 °C)

Thermal conductivity / W m^-1K^-1:13.3

Melting point / °C:1074

Boiling point / °C:1794

Heat of fusion / kJ mol^-1:10.9

Heat of vaporization / kJ mol^-1:164.8

Heat of atomization / kJ mol^-1:206.1

1st ionization energy / kJ mol^-1:544.53

2nd ionization energy / kJ mol^-1:1068.10

3rd ionization energy / kJ mol^-1:2257.77

in the atmosphere / ppm:-

in the Earth's crust / ppm:3.5

in the oceans / ppm:0.0000002