62 2 · 8 · 18 · 24 · 8 · 2

Samarium, Sm, element 62

Lanthanide· Period 6· f-block

Configuration [Xe]4f⁶6s²

Atomic weight: 150.36Da
Phase: solid
Density: 7.52g/cm³
Melting point: 1,345.15K 1,072 °C
Boiling point: 2,067.15K 1,794 °C
Electronegativity: 1.17

Soft silvery metallic element, belongs to the lanthanoids. Seven natural isotopes, Sm-147 is the only radioisotope, and has a half-life of 2.5*10^11 years. Used for making special alloys needed in the production of nuclear reactors. Also used as a neutron absorber. Small quantities of samarium oxide is used in special optical glasses. The largest use of the element is its ferromagnetic alloy which produces permanent magnets that are five times stronger than magnets produced by any other material. Discovered by Francois Lecoq de Boisbaudran in 1879. Description from mendeleev.

Back to the table

The outermost shell: the valence electronsThe inner shellsThe nucleus One bead for each electron, on the ring of its shell, counted from the nucleus out. The rings turn at their own pace; the model is Bohr's picture of the atom, which places electrons in shells but not on true orbits.

Atomic properties

5 of 5 fields have a value for samarium

Atomic weight The standard atomic weight. For an element with no stable isotope, the mass of its longest-lived isotope.: 150.36Da; Source: mendeleev
Electron configuration: [Xe]4f⁶6s²; Source: mendeleev
Uncertainty of the atomic weight: 0.02Da; Source: mendeleev
Electron configuration in full The electron configuration with the noble-gas core written out.: 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d¹⁰4f⁶5s²5p⁶6s²; Source: Worked outfrom electron configuration
Electrons in each shell Counted from the electron configuration, from the first shell outward.: 2 · 8 · 18 · 24 · 8 · 2; Source: Worked outfrom electron configuration

Screening of each subshell

Clementi's screening constants: how much of the nucleus's charge the other electrons hide from an electron in each subshell. What is left is the effective nuclear charge it feels.

Subshell	Screening σ	Effective charge Z − σ
1s	1.2217	60.7783
2s	16.2652	45.7348
2p	4.269	57.731
3s	19.9736	42.0264
3p	19.5815	42.4185
3d	13.7711	48.2289
4s	29.7076	32.2924
4p	30.912	31.088
4d	33.7604	28.2396
4f	38.4684	23.5316
5s	43.751	18.249
5p	45.719	16.281
6s	53.9882	8.0118