Terbium is a chemical element in the Periodic Table marked with the atomic number of 65 and with the chemical symbol Tb. This chemical element belongs to period 6 elements and the Lanthanide category. Similar to the rest of the Lanthanide elements Terbium possesses some metallic properties. In the Periodic Table Terbium is preceded by Gadolinium and is followed by Dysprosium.


Terbium is usually considered as a rare earth element, even though it is far from the least abundant chemical elements on Earth. It is relatively soft, ductile and malleable metallic element, which can be cut with a knife. It does not occur freely in nature, but is abundant in various minerals like xenotime, euxenite, monazite, cerite, and gadolinite. This particular element has no known biological roles for human beings and other living organisms and its toxicity levels are low to moderate. It has various applications in electronics, lighting installations, fuel cells, and sonar installations.


Physical Characteristics of Terbium

In terms of physical characteristics Terbium is a solid, relatively soft Lanthanide element. It has a silvery-white metallic finish and can be easily cut with a knife. It is notably malleable and ductile. Compared to other Lanthanide elements this particular chemical element is quite stable in air. It has a typical hexagonal close-packed crystal structure. The Terbium cation has a bright lemon-yellowish color and is brilliantly fluorescent. When subjected to temperatures lower than 219K Terbium has a ferromagnetic ordering. Compared to most chemical elements Terbium has notably high melting and boiling points. When it’s dissolved in dilute sulfuric acid this chemical’s ions have a distinguishable pale pink color scheme.


Chemical Properties of Terbium


Atomic Number – 65

Group – n/a

Period – 6

Block – f

Electronic Configuration – 4f9 6s2

Relative Atomic Mass – 158.9253 (158.92535 g/mol)

Molecular Weight – 158.9253

Electronegativity – 1.2

Density (G CM-3) – 8.23 g/cm3 at room temperature; 7.65 g/cm3 in liquid state

Melting Point – 1629 K; 1356 °C; 2473 °F

Boiling Point – 3396 K; 3123 °C; 5653 °F

Atomic Radius – 177 pm

Isotopes – 1

Electronic Shell – 2, 8, 18, 27, 8, 2


Discovery of Terbium

A Swedish chemist, named Carl Gustaf Mosander, is credited with the discovery of the element Terbium. He analyzed a sample of Yttrium oxide back in 1843 and found that one of the impurities in the compound was, in fact, the presence of Terbium’s pink ions. He originally named the newly discovered element Terbia. The first pure isolation of Terbium was carried out only after the ion exchange technology advanced.


Recognized by: Carl Gustaf Mosander (1843)

Known and discovered by: Carl Gustaf Mosander (1843)

Named by: Carl Gustaf Mosander


Uses and role of Terbium

Terbium does not play any biological role in human beings or other living organisms on Earth. However, it does have several scientific purposes and commercial uses mainly focused around electronics and lighting installations.


Terbium is used as a crystal stabilizer for high-temperature fuel cells. It also plays a big role as a dopant for Strontium molybdate, Calcium tungstate, and Calcium fluorite. This Lanthanide chemical element is also used in various alloys for the manufacturing of electronics. For example, it has valuable applications in sonar systems, actuators, naval sensors, and in various other magneto-mechanical gadgets. Terbium is also used in fluorescent lamps, incandescent lighting installations, phosphor for TV tubes, and so on. One of the scientific applications of Terbium is as a probe in biochemistry due to its brilliant fluorescence.


Terbium on Earth

While Terbium is not among the rarest elements on Earth, it is often considered as a rare earth element. It does occur freely in nature, but only in mixture with other elements. It can be found in various minerals and ores like monazite, xenotime, euxenite, cerite and gadolinite. Terbium makes up around 1.2mg per kilogram of Earth’s crust.



Various ground-breaking studies claim that Terbium and its ions’ colorful specter could soon make a cutting-edge nanolight revolution in the world we know today, which could significantly boost not only trivial technology like TV sets, but could also have positive and vital effects on various cancer treatment techniques.