Rare Earth Metals

Lanthanides and actinides

Why are the rare earth elements separated from others?

Simply because there was not enough room on the table! They were moved down because it would just take up too much space!

History of the Rare Earth Metals

Cerium (Ce) - Cerium was discovered in 1803 by Jöns Jacob Berzelius, Wilhelm Hisinger and by Martin Klaproth. It was isolated from a mineral from an iron mine at Bastn°s.

Melting point - 1068 K

Boiling point - 3633 K

Praseodymium (Pr) - Carl Auer von Welsbach found Praseodymium in 1885 by separating didymia into two types of earths. These earths were praseodymia and neodymia.

Melting point - 1208 K

Boiling point - 3563 K

Neodymium (Nd) - The other element that von Welsbach discovered when he split up didymia in 1885.

Melting point - 1297 K

Boiling point - 3373 K

Promethium (Pm) - Bohuslav Brauner predicted the existence of Promethium in 1902. No one could confirm that it existed though, because of how hard it was to separate promethium from other elements. In 1946, Clinton Laboratories discovered it by analyzing byproducts of nuclear fission.

Melting point - 1373 K

Boiling point - 3273 K

Samarium (Sm) - Jean Charles Galissard de Marignac discovered Samarium in 1853 using a spectroscope's sharp absorption lines.

Melting point - 1345 K

Boiling point - 2076 K

Europium (Eu) - Eug/ne-Antole Demarcay discovered Europium in 1901 when he separated a material containing a mostly samarium.

Melting point - 1099 K

Boiling point - 1800 K

Gadolinium (Gd) - Spectroscopic lines due to gadolinium were observed by Jean Charles Galissard de Marignac in 1880 in samples of didymia and gadolinite.

Melting point - 1585 K

Boiling point - 3523 K

Terbium (Tb) - Terbium was discovered by Gustav Mosander in 1843. He detected it is as an impurity in yttria which is yttrium oxide.

Melting point - 1629 K

Boiling point - 3503 K

Dysprosium (Dy) - A little dysprosium oxide was identified in 1886 by Paul-Emile Lecoq de Boisbaudran as an impurity in erbia (erbium oxide). The pure form did not get discovered until the 1950s when the development of ion-exchange separation and metallographic reduction techniques.

Melting point - 1680 K

Boiling point - 2840 k

Holmium (Ho) - Per Theodor Cleve of Sweden discovered holmium while working on erbia earth (erbium oxide). Holmium oxide (holmia) was there as an impurity in the erbia. Pure holmia, the yellow oxide, was prepared in 1911 by Homberg.

Melting point - 1734 K

Boiling point - 2993 K

Erbium (Er) - In 1842 Gustav Mosander separated "yttria", found in the mineral gadolinite, into three fractions which he called yttria, erbia, and terbia.

Melting point - 1802 K

Boiling point - 3141 K

Thulium (Tm) - Per Theodor Cleve of Sweden discovered holmium in 1879 while working on erbia earth (erbium oxide). Thulium oxide (holmia) was present as an impurity in the erbia

Melting point - 1818 K

Boiling point - 2223

Ytterbium (Yb) - In 1878 Marignac discovered a component, which he called ytterbia, in the earth then known as erbia. In 1907, Urbain separated ytterbia into two components, which he called neoytterbia and lutecia.

Melting point - 1097 K

Boiling point - 1469 K

Lutetium (Lu) - In 1907, Georges Urbain described a process by which Marignac's ytterbium (1879) could be separated into the two elements, ytterbium (neoytterbium) and lutetium.

Melting point - 1925 K

Boiling point - 3675 K

Thorium (Th) - Thorium was discovered by Berzelius in 1828 in a mineral given to him by the Reverend Has Morten Thrane Esmark

Melting point - 2115 K

Boiling point - 5093 K

Protactinium (Pa) - Protactinium was identified by Fajans and GΔhring in 1913 who named the new element brevium ("brief"). The metal itself was not isolated until 1934 when Aristid Grosse developed two methods. One involved reduction of the pentoxide Pa2O5 with a stream of electrons in a vacuum and the second involved heating the iodide PaI5 under vacuum.

Melting point - 1841 K

Boiling point - 4300 K

Uranium (U) - A yellow glass containing more than 1% uranium oxide dating back to 79 AD was found near Naples in Italy. Uranium metal itself was first isolated in 1841 by Eugene-Melchoir Peligot, who reduced the anhydrous chloride UCl4 with potassium. The radioactive nature of uranium was not found for another 55 years when in 1896 Henri Becquerel detected its radioactivity.

Melting point - 1405.3 K

Boiling point - 4200 K

Neptunium (Np) - Neptunium was the first synthetic transuranium element of the actinide series. It was discovered by McMillan and Abelson in 1940 at Berkeley, California, USA, who bombarded uranium with neutrons produced from a cyclotron.

Melting point - 910 K

Boiling point - 4300 K

Plutonium (Pu) - Plutonium was synthesized by Seaborg, McMillan, Kennedy and Wahl in 1940 by deuteron bombardment of uranium in a cyclotron (a device used to accelerate atomic particles) at Berkeley, California, USA.

Melting point - 912.5 K

Boiling point - 3503 K

Americium (Am) - Americium was was identified by Seaborg and others in 1944 as the result of successive neutron capture reactions by plutonium isotopes in a nuclear reactor.

Melting point - 1449 K

Boiling point - 2880 K

Curium (Cm) - In 1944, Curium was discovered as a result of helium ion bombardment of the plutonium isotope239Pu. Three years later visible amounts of the hydroxide were isolated by Werner and Perlman. In 1951, the same workers prepared curium in its elemental form for the first time.

Melting point - 1613 K

Boiling point - 3383 K

Berkelium (Bk) - Berkelium was discovered in December 1949 at Berkeley, Californi, USA, by Ghiorso and others by cyclotron bombardment of milligram amounts of americium with helium ions.

Melting point - 1259 K

Californium (Cf) - Californium was produced by Ghiorso and others at the University of California, Berkeley, USA in 1950 who bombarded242Cm with helium ions.

Melting point - 1173 K

Einsteinium (Es) - Einsteinium was identified by Ghiorso and others (Berkeley, California, USA) in 1952 in radioactive debris from the first large thermonuclear bomb explosion.

Melting point - 1133 K

Fermium (Fm) - Fermium was identified by Ghiorso and coworkers (Berkeley, California, USA) in 1952 in the radioactive debris from a thermonuclear explosion in the Pacific.

Melting point - about 1800 K

Mendelevium (Md) - Mendelevium, the ninth transuranium element of the actinide series to be discovered, was first identified by Seaborg and others in 1955 as a product of the bombardment of the einsteinium isotope253Es with helium ions.

Melting point - 1100 K

Nobelium (No) - A team working in Stockholm reported in 1957 an isotope whose atomic number is 102. They made this isotope by bombardment of 244Cm with 13C ions

Melting point - About 1100 K

Lawrencium (Lr) - Element 103, lawrencium, was discovered in 1961 by Ghiorso and others in Berkeley, California, USA, who bombarded a californium target with boron ions.

Melting point - About 1900 K

Number of Valence electrons

Every element in the Lanthanide series will have 3 valence electrons.

The elements in the Actinide series can vary from 3-6 valence electrons.

Environmental or Safety concerns about these Elements

The physical process of removing the ores from the ground is disruptive to the environment.
Most rare earth elements are mined through open pit mining, which involves opening the
surface of the earth using heavy equipment and machinery. Creating this disruption on the
surface of the earth disrupts thriving ecosystems. Furthermore, mines are the point source of release for three major contaminants: are radionuclides, rare earth elements, and dust and metal. Each of these contaminants escapes the mines in different ways and they each have different harmful effects on the environment

Disposal of these elements can also harm the environment. Water can be contaminated in three ways: sedimentation, acid drainage, and metals deposition, and once contaminated is difficult to restore to its original quality.

Uses for Rare Earth Metals

Europium is used for color tv. Although there was color tv before Europium was used, it was rather weak.

Erbium is used to create most pink shades. This is used for staining glass, and on sunglasses, vases, etc.

Neodymium are used as magnets. This is because they are much stronger, and more compact. Not much more to it!

Links on google maps for where some elements were found

Educational video about Lanthanides and Actinides!


"The Periodic Table." Periodic Table of Elements and Chemistry. N.p., n.d. Web. 12 Jan. 2014.

"Home of the Periodic Table." Periodic Table of the Elements by WebElements. N.p., n.d. Web. 14 Jan. 2014.