Samarium (Sm): electron configuration, atomic mass and facts
Samarium (Sm) is element 62 of the periodic table, a lanthanide in period 6 (f-block). Its electron configuration is [Xe] 4f6 6s2, with electrons arranged in shells 2, 8, 18, 24, 8, 2, and its standard atomic weight is 150.36 u.
▶ Watch Samarium’s electrons orbit in the interactive periodic tableSamarium at a glance
| Symbol | Sm |
|---|---|
| Atomic number | 62 |
| Atomic mass | 150.36 u |
| Category | Lanthanide |
| Group | f-block (no group number) |
| Period | 6 |
| Block | f-block |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f6 5s2 5p6 6s2 |
| Noble-gas shorthand | [Xe] 4f6 6s2 |
| Electrons per shell | 2, 8, 18, 24, 8, 2 |
| Electronegativity (Pauling) | 1.17 |
| State at 20 °C | solid |
Where is Samarium on the periodic table?
Samarium is in period 6 of the f-block, the lanthanide row printed below the main table. It has 6 electron shells, and this row is where the 4f subshell fills.
How to work out the electron configuration of Samarium
Put 62 electrons into subshells in order of rising energy, filling each before starting the next: 1s² (2), 2s² (4), 2p⁶ (10), 3s² (12), 3p⁶ (18), 4s² (20), 3d¹⁰ (30), 4p⁶ (36), 5s² (38), 4d¹⁰ (48), 5p⁶ (54), 6s² (56), 4f⁶ (62). In shorthand, [Xe] stands for the 54 electrons of xenon, giving [Xe] 4f⁶ 6s².
How electronegative is Samarium?
Samarium has a Pauling electronegativity of 1.17, ranking 81 of the 100 elements with a known value (fluorine is highest at 3.98). That is low: it tends to give up electrons and form positive ions.
Frequently asked questions
What is the electron configuration of Samarium?
The electron configuration of Samarium (Sm) is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f6 5s2 5p6 6s2. In noble-gas shorthand it is written [Xe] 4f6 6s2.
How many electrons does Samarium have in each shell?
Samarium has 62 electrons arranged in shells as 2, 8, 18, 24, 8, 2.
What is the atomic mass of Samarium?
The standard atomic weight of Samarium is 150.36 u, so one mole of Samarium atoms has a mass of about 150.36 g.
Is Samarium a metal?
Yes. Samarium is a lanthanide.
Explore nearby elements
More lanthanides: Praseodymium, Neodymium, Promethium, Europium, Gadolinium, Terbium. See all elements on the periodic table.