Holmium (67)

Holmium is relatively soft and malleable, and is stable in dry air at room temperature. It oxidizes rapidly in moist air and at elevated temperatures. The metal has unusual magnetic properties. The metal is a rare earth metal found in monazite, gadolinite and other minerals.

•Name: Holmium
•Symbol: Ho
•Atomic number: 67
•Atomic weight: 164.93032 (2) 
•Standard state: solid at 298 K
•CAS Registry ID: 7440-60-0
•Group in periodic table: 
•Group name: Lanthanoid
•Period in periodic table: 6 (lanthanoid)
•Block in periodic table: f-block
•Color: silvery white
•Classification: Metallic

Historical information
Holmium was discovered by J. L. Soret and Delafontaine at 1878 in Switzerland. Origin of name: from the Greek word "Holmia" meaning "Sweden". Per Theodor Cleve of Sweden discovered holmium while working on erbia earth (erbium oxide). Holmium oxide (holmia) was present as an impurity in the erbia. The element is named after Cleve's native city. Pure holmia, the yellow oxide, was prepared by Homberg in 1911.

Physical properties 
•Melting point: 1734 [or 1461 °C (2662 °F)] K
•Boiling point: 2993 [or 2720 °C (4928 °F)] K
•Density of solid: 8795 kg m-3

Orbital properties
•Ground state electron configuration: [Xe].4f11.6s2
•Shell structure: 2.8.18.29.8.2
•Term symbol: 4I15/2

Isolation
Holmium metal is available commercially so it is not normally necessary to make it in the laboratory, which is just as well as it is difficult to isolate as the pure metal. This is largely because of the way it is found in nature. The lanthanoids are found in nature in a number of minerals. The most important are xenotime, monazite, and bastnaesite. The first two are orthophosphate minerals LnPO4 (Ln deonotes a mixture of all the lanthanoids except promethium which is vanishingly rare) and the third is a fluoride carbonate LnCO3F. Lanthanoids with even atomic numbers are more common. The most comon lanthanoids in these minerals are, in order, cerium, lanthanum, neodymium, and praseodymium. Monazite also contains thorium and ytrrium which makes handling difficult since thorium and its decomposition products are radioactive.

For many purposes it is not particularly necessary to separate the metals, but if separation into individual metals is required, the process is complex. Initially, the metals are extracted as salts from the ores by extraction with sulphuric acid (H2SO4), hydrochloric acid (HCl), and sodium hydroxide (NaOH). Modern purification techniques for these lanthanoid salt mixtures are ingenious and involve selective complexation techniques, solvent extractions, and ion exchange chromatography. 

Pure holmium is available through the reduction of HoF3 with calcium metal.

2HoF3 + 3Ca → 2Ho + 3CaF2

This would work for the other calcium halides as well but the product CaF2 is easier to handle under the reaction conditions (heat to 50°C above the melting point of the element in an argon atmosphere). Excess calcium is removed from the reaction mixture under vacuum.

 

Dysprosium (66)

Dysprosium [DIS-PROH-SEE-UM] has a metallic, bright silver lustre. It is relatively stable in air at room temperature, but dissolves readily, with the evolution (release) of hydrogen, in mineral acids. The metal is soft enough to be cut with a knife and can be machined without sparking if overheating is avoided. It is a rare earth metal found in minerals such as xenotime, monazite and bastnaesite.

•Name: Dysprosium
•Symbol: Dy
•Atomic number: 66
•Atomic weight: 162.500 (1) [see note g]
•Standard state: solid at 298 K
•CAS Registry ID: 7429-91-6
•Group in periodic table: 
•Group name: Lanthanoid
•Period in periodic table: 6 (lanthanoid)
•Block in periodic table: f-block
•Color: silvery white
•Classification: Metallic

Historical information
Dysprosium was discovered by Paul Emile Lecoq de Boisbaudran at 1886 in France, as an impurity in erbia (erbium oxide), but the element itself not isolated at that time. Origin of name: from the Greek word "dysprositos" meaning "hard to obtain". Neither the oxide nor the metal was available in relatively pure form until the 1950s following the development of ion-exchange separation and metallographic reduction techniques.

Physical properties 
•Melting point: 1680 [or 1407 °C (2565 °F)] K
•Boiling point: 2840 [or 2567 °C (4653 °F)] K
•Density of solid: 8551 kg m-3

Orbital properties
•Ground state electron configuration: [Xe].4f10.6s2
•Shell structure: 2.8.18.28.8.2
•Term symbol: 5I8

Isolation
Dysprosium metal is available commercially so it is not normally necessary to make it in the laboratory, which is just as well as it is difficult to isolate as the pure metal. This is largely because of the way it is found in nature. The lanthanoids are found in nature in a number of minerals. The most important are xenotime, monazite, and bastnaesite. The first two are orthophosphate minerals LnPO4 (Ln deonotes a mixture of all the lanthanoids except promethium which is vanishingly rare) and the third is a fluoride carbonate LnCO3F. Lanthanoids with even atomic numbers are more common. The most comon lanthanoids in these minerals are, in order, cerium, lanthanum, neodymium, and praseodymium. Monazite also contains thorium and ytrrium which makes handling difficult since thorium and its decomposition products are radioactive.

For many purposes it is not particularly necessary to separate the metals, but if separation into individual metals is required, the process is complex. Initially, the metals are extracted as salts from the ores by extraction with sulphuric acid (H2SO4), hydrochloric acid (HCl), and sodium hydroxide (NaOH). Modern purification techniques for these lanthanoid salt mixtures are ingenious and involve selective complexation techniques, solvent extractions, and ion exchange chromatography. 

Pure dysprosium is available through the reduction of DyF3 with calcium metal.

2DyF3 + 3Ca → 2Dy + 3CaF2

This would work for the other calcium halides as well but the product CaF2 is easier to handle under the reaction conditions (heat to 50°C above the melting point of the element in an argon atmosphere). Excess calcium is removed from the reaction mixture under vacuum.

 

Terbium (65)

Terbium is reasonably stable in air. It is a silvery-grey metal, and is malleable, ductile, and soft enough to be cut with a knife. It is a rare earth metal found in cerite, gadolinite and monazite. The element itself was isolated only recently.

•Name: Terbium
•Symbol: Tb
•Atomic number: 65
•Atomic weight: 158.92535 (2) 
•Standard state: solid at 298 K
•CAS Registry ID: 7440-27-9
•Group in periodic table: 
•Group name: Lanthanoid
•Period in periodic table: 6 (lanthanoid)
•Block in periodic table: f-block
•Color: silvery white
•Classification: Metallic

Historical information
Terbium was discovered by Carl Gustav Mosander at 1843 in Sweden. He detected it is as an impurity in yttria which is yttrium oxide, Y2O3. Named after "Ytterby", a town in Sweden.

Physical properties 
•Melting point: 1629 [or 1356 °C (2473 °F)] K
•Boiling point: 3503 [or 3230 °C (5846 °F)] K
•Density of solid: 8219 kg m-3

Orbital properties
•Ground state electron configuration: [Xe].4f9.6s2
•Shell structure: 2.8.18.27.8.2
•Term symbol: 6H15/2

Isolation
Terbium metal is available commercially so it is not normally necessary to make it in the laboratory, which is just as well as it is difficult to isolate as the pure metal. This is largely because of the way it is found in nature. The lanthanoids are found in nature in a number of minerals. The most important are xenotime, monazite, and bastnaesite. The first two are orthophosphate minerals LnPO4 (Ln deonotes a mixture of all the lanthanoids except promethium which is vanishingly rare) and the third is a fluoride carbonate LnCO3F. Lanthanoids with even atomic numbers are more common. The most comon lanthanoids in these minerals are, in order, cerium, lanthanum, neodymium, and praseodymium. Monazite also contains thorium and ytrrium which makes handling difficult since thorium and its decomposition products are radioactive.

For many purposes it is not particularly necessary to separate the metals, but if separation into individual metals is required, the process is complex. Initially, the metals are extracted as salts from the ores by extraction with sulphuric acid (H2SO4), hydrochloric acid (HCl), and sodium hydroxide (NaOH). Modern purification techniques for these lanthanoid salt mixtures are ingenious and involve selective complexation techniques, solvent extractions, and ion exchange chromatography. 

Pure terbium is available through the reduction of TbF3 with calcium metal.

2TbF3 + 3Ca → 2Tb + 3CaF2

This would work for the other calcium halides as well but the product CaF2 is easier to handle under the reaction conditions (heat to 50°C above the melting point of the element in an argon atmosphere). Excess calcium is removed from the reaction mixture under vacuum.

 

Gadolinium (64)

Gadolinium is silvery white, has a metallic luster, and is is malleable (capable of being extended or shaped by beating with a hammer or by the pressure of rollers) and ductile (capable of being drawn out into wire or threads). It is ferromagnetic (strongly attracted by a magnet).

The metal is relatively stable in dry air, but in moist air it tarnishes with the formation of a loosely adhering oxide film which "spalls" off and exposes more surface to oxidation. The metal reacts slowly with water and is soluble in dilute acid. Gadolinium has the highest thermal neutron capture cross-section of any known element. 

•Name: Gadolinium
•Symbol: Gd
•Atomic number: 64
•Atomic weight: 157.25 (3) [see note g]
•Standard state: solid at 298 K
•CAS Registry ID: 7440-54-2
•Group in periodic table: 
•Group name: Lanthanoid
•Period in periodic table: 6 (lanthanoid)
•Block in periodic table: f-block
•Color: silvery white
•Classification: Metallic

Historical information
Gadolinium was discovered by Jean de Marignac at 1880 in Switzerland, and named for J. "Gadolin", a Finnish chemist and minerologist. Spectroscopic lines due to gadolinium were observed in samples of didymia and gadolinite. Gadolinia, the oxide of gadolinium, was separated by Paul-Emile Loq de Biosbaudran in 1886. The element was named for the mineral gadolinite from which this rare earth was originally obtained. The element itself was isolated only recently. 

Physical properties 
•Melting point: 1585 [or 1312 °C (2394 °F)] K
•Boiling point: 3523 [or 3250 °C (5882 °F)] K
•Density of solid: 7901 kg m-3

Orbital properties
•Ground state electron configuration: [Xe].4f7.5d1.6s2
•Shell structure: 2.8.18.25.9.2
•Term symbol: 9D2

Isolation
Gadolinium metal is available commercially so it is not normally necessary to make it in the laboratory, which is just as well as it is difficult to isolate as the pure metal. This is largely because of the way it is found in nature. The lanthanoids are found in nature in a number of minerals. The most important are xenotime, monazite, and bastnaesite. The first two are orthophosphate minerals LnPO4 (Ln deonotes a mixture of all the lanthanoids except promethium which is vanishingly rare) and the third is a fluoride carbonate LnCO3F. Lanthanoids with even atomic numbers are more common. The most comon lanthanoids in these minerals are, in order, cerium, lanthanum, neodymium, and praseodymium. Monazite also contains thorium and ytrrium which makes handling difficult since thorium and its decomposition products are radioactive.

For many purposes it is not particularly necessary to separate the metals, but if separation into individual metals is required, the process is complex. Initially, the metals are extracted as salts from the ores by extraction with sulphuric acid (H2SO4), hydrochloric acid (HCl), and sodium hydroxide (NaOH). Modern purification techniques for these lanthanoid salt mixtures are ingenious and involve selective complexation techniques, solvent extractions, and ion exchange chromatography. 

Pure gadolinium is available through the reduction of GdF3 with calcium metal.

2GdF3 + 3Ca → 2Gd + 3CaF2

This would work for the other calcium halides as well but the product CaF2 is easier to handle under the reaction conditions (heat to 50°C above the melting point of the element in an argon atmosphere). Excess calcium is removed from the reaction mixture under vacuum.

Europium (63)

Europium ignites in air at about 150 to 180°C. Europium is about as hard as lead and is quite ductile. It is the most reactive of the rare earth metals, quickly oxidising in air. It resembles calcium in its reaction with water. It is used in television screens to produce a red colour.

•Name: Europium
•Symbol: Eu
•Atomic number: 63
•Atomic weight: 151.964 (1) [see note g]
•Standard state: solid at 298 K
•CAS Registry ID: 7440-53-1
•Group in periodic table: 
•Group name: Lanthanoid
•Period in periodic table: 6 (lanthanoid)
•Block in periodic table: f-block
•Color: silvery white
•Classification: Metallic

Historical information
Origin of name (betcha could've guessed this one!)- named after "Europe". The discovery of europium is generally credited to Eugene-Antole Demarcay, who separated the earth in reasonably pure form in 1901 from a material containing largely samarium. Pure europium metal was not isolated until much more recently. 

Physical properties 
•Melting point: 1099 [or 826 °C (1519 °F)] K
•Boiling point: 1800 [or 1527 °C (2781 °F)] K
•Density of solid: 5244 kg m-3

Orbital properties
•Ground state electron configuration: [Xe].4f7.6s2
•Shell structure: 2.8.18.25.8.2
•Term symbol: 8S7/2

Isolation
Europium metal is available commercially so it is not normally necessary to make it in the laboratory, which is just as well as it is difficult to isolate as the pure metal. This is largely because of the way it is found in nature. The lanthanoids are found in nature in a number of minerals. The most important are xenotime, monazite, and bastnaesite. The first two are orthophosphate minerals LnPO4 (Ln deonotes a mixture of all the lanthanoids except promethium which is vanishingly rare) and the third is a fluoride carbonate LnCO3F. Lanthanoids with even atomic numbers are more common. The most comon lanthanoids in these minerals are, in order, cerium, lanthanum, neodymium, and praseodymium. Monazite also contains thorium and ytrrium which makes handling difficult since thorium and its decomposition products are radioactive.

For many purposes it is not particularly necessary to separate the metals, but if separation into individual metals is required, the process is complex. Initially, the metals are extracted as salts from the ores by extraction with sulphuric acid (H2SO4), hydrochloric acid (HCl), and sodium hydroxide (NaOH). Modern purification techniques for these lanthanoid salt mixtures are ingenious and involve selective complexation techniques, solvent extractions, and ion exchange chromatography. 

Pure europium is available through the electrolysis of a mixture of molten EuCl3 and NaCl (or CaCl2) in a graphite cell which acts as cathode using graphite as anode. The other product is chlorine gas.