What Is Samarium?
Samarium is a chemical element with the symbol Sm and atomic number 62, part of the lanthanide series of rare earth elements.
A hard, silvery metal. Samarium-cobalt magnets work at higher temperatures than neodymium.
As a lanthanide in Period 6 and Group 3 (Transition Metals), samarium's placement on the table reflects its electron configuration of [Xe] 4f⁶ 6s², which governs its bonding behavior and the type of compounds it typically forms.
Position on the Periodic Table
Samarium is located in Period 6, an unusually long row that includes the entire lanthanide series.
Within that row, samarium sits in Group 3 (Transition Metals), alongside elements that share a similar number of valence electrons and, by extension, similar chemical behavior.
This position is not arbitrary — the periodic table was deliberately organized so that an element's row and column reveal its expected reactivity, bonding pattern, and physical state at a glance.
Physical & Chemical Properties
Samarium has an atomic mass of 150.360 u and a density of 7.52 g/cm³. Its melting point is 1072°C and its boiling point is 1794°C.
Samarium displays the typical lanthanide combination of a silvery appearance and chemistry dominated by its f-orbital electrons.
Electron Configuration Explained
Samarium's electron configuration is [Xe] 4f⁶ 6s², describing how its electrons are distributed across shells and subshells around the nucleus.
Reading the configuration in order shows electrons filling shells of increasing energy, following the standard Aufbau principle that explains how atomic structure builds up across the periodic table.
The outermost (valence) electrons shown in this configuration are what ultimately determine samarium's chemical reactivity and the type of bonds it forms with other elements.
History & Discovery
Samarium was formally discovered in 1879, P.É. Lecoq de Boisbaudran, identified through the careful isolation and analytical techniques typical of that era's chemical research.
Many elements from this period were anticipated by Dmitri Mendeleev's periodic table, which successfully predicted gaps corresponding to undiscovered elements well before laboratory instruments existed to confirm them directly.
What Is Samarium Used For?
Samarium's specific properties make it useful in several applications, including:
- High-temp magnets
- Neutron capture
- Cancer treatment
- Optical lasers
- Headphones
These uses reflect samarium's underlying classification as a lanthanide, since the same properties that define its category in chemistry also determine where it becomes practically useful.
Fun Facts About Samarium
- Samarium-cobalt magnets are used in motors that operate above 150°C.
- Samarium is element number 62 on the periodic table, in Period 6 and Group 3.
- Its standard atomic mass is 150.360 u, calculated from the natural abundance of its isotopes.
Frequently Asked Questions
What is Samarium's atomic number?
Samarium has atomic number 62.
What is Samarium's chemical symbol?
Samarium's symbol is Sm.
What group and period is Samarium in?
Samarium is in Period 6, Group 3 (Transition Metals).
What is Samarium's atomic mass?
Samarium's standard atomic mass is 150.360 u.