Hafnium (72)

Most zirconium minerals contain 1 to 3% hafnium. Hafnium is a ductile metal with a brilliant silver lustre. Its properties are influenced considerably by the impurities of zirconium present. Of all the elements, zirconium and hafnium are two of the most difficult to separate. Hafnium is a Group 4 transition element.

Because hafnium has a good absorption cross section for thermal neutrons (almost 600 times that of zirconium), has excellent mechanical properties, and is extremely corrosion resistant, it is used for nuclear reactor control rods.

Hafnium carbide is the most refractory binary composition known, and the nitride is the most refractory metal nitride (m.p. 3310°C).

•Name: Hafnium
•Symbol: Hf
•Atomic number: 72
•Atomic weight: 178.49 (2) 
•Standard state: solid at 298 K
•CAS Registry ID: 7440-58-6
•Group in periodic table: 4
•Group name: (none)
•Period in periodic table: 6 
•Block in periodic table: d-block
•Color: grey steel
•Classification: Metallic

Historical information
Hafnium was discovered by Dirk Coster and George Charles von Hevesy at 1923 in Denmark, though it was thought to be present in various zirconium minerals many years prior to its discovery. Origin of name is from the Latin name "Hafnia" meaning "Copenhagen." It was finally identified in zircon (a zirconium ore) from Norway, by means of X-ray spectroscopic analysis. It was named in honour of the city in which the discovery was made. A number of earlier claims seem less likely.

Most zirconium minerals contain 1 to 3% hafnium and it is their chemical similarity which made their separation difficult. It was originally separated from zirconium by repeated and tedious recrystallization of the double ammonium or potassium fluorides.

Physical properties 
•Melting point: 2506 [or 2233 °C (4051 °F)] K
•Boiling point: 4876 [or 4603 °C (8317 °F)] K
•Density of solid: 13310 kg m-3

Orbital properties
•Ground state electron configuration: [Xe].4f14.5d2.6s2
•Shell structure: 2.8.18.32.10.2
•Term symbol: 3F2

Isolation
Isolation: hafnium extraction is always associated with its removal from zirconium as it is a contaminant of all zirconium minerals. Solvent extraction methods are used ot spearate the two metals but the process is not easy. These make use of the differential solubilities of the metal thiocyantes (thiocyanate is SCN-) in methyl isobutyl ketone.

 

Lutetium (71)

Pure metallic lutetium has been isolated only in recent years and is one of the more difficult to prepare. It can be prepared by the reduction of anhydrous LuCl3 or LuF3 by an alkali or alkaline earth metal.

The metal is silvery white and relatively stable in air. It is a rare earth metal and perhaps the most expensive of all rare elements. It is found in small amounts with all rare earth metals, and is very difficult to separate from other rare elements.

•Name: Lutetium
•Symbol: Lu
•Atomic number: 71
•Atomic weight: 174.9668
•Standard state: solid at 298 K
•CAS Registry ID: 7439-94-3
•Group in periodic table: 3
•Group name: (none)
•Period in periodic table: 6 
•Block in periodic table: d-block
•Color: silvery white
•Classification: Metallic

Hstorical information
Lutetium was discovered by Georges Urbain in France and Carl Auer von Welsbach at 1907 in France, around the same time and independently. Origin of name is from the Greek word "Lutetia" meaning "Paris". In 1907, Georges Urbain described a process by which Marignac's ytterbium (1879) could be separated into the two elements, ytterbium (neoytterbium) and lutetium. These elements were identical with "aldebaranium" and "cassiopeium", independently discovered by von Welsbach at about the same time. 

Physical properties 
•Melting point: 1925 [or 1652 °C (3006 °F)] K
•Boiling point: 3675 [or 3402 °C (6156 °F)] K
•Density of solid: 9841 kg m-3

Orbital properties
•Ground state electron configuration: [Xe].4f14.5d1.6s2
•Shell structure: 2.8.18.32.9.2
•Term symbol: 2D3/2

Isolation
Lutetium 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 lutetium is available through the reduction of LuF3 with calcium metal.

2LuF3 + 3Ca → 2Lu + 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.

 

Ytterbium (70)

Ytterbium has a bright silvery lustre, is soft, malleable, and quite ductile. While the element is fairly stable, it should be kept in closed containers to protect it from air and moisture. Ytterbium is readily attacked and dissolved by mineral acids and reacts slowly with water.

•Name: Ytterbium
•Symbol: Yb
•Atomic number: 70
•Atomic weight: 173.054 (5) [see note g]
•Standard state: solid at 298 K
•CAS Registry ID: 7440-64-4
•Group in periodic table: 
•Group name: Lanthanoid
•Period in periodic table: 6 (lanthanoid)
•Block in periodic table: f-block
•Colour: silvery white
•Clasification: Metallic

Historical information
Ytterbium was discovered by Jean de Marignac at 1878 in Switzerland, which he named after the village of "Ytterby" near Vaxholm in Sweden. 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. The elements in these earths are now known as ytterbium and lutetium, respectively. These elements are identical with aldebaranium and cassiopeium, discovered independently and at about the same time by von Welsbach. The impure element was first prepared by Klemm and Bonner in 1937 who reduced ytterbium trichloride with potassium. Daane, Dennison, and Spedding prepared a purer form in 1953 from which the chemical and physical properties of the element could be determined.

Physical properties 
•Melting point: 1097 [or 824 °C (1515 °F)] K
•Boiling point: 1469 [or 1196 °C (2185 °F)] K
•Density of solid: 6570 kg m-3

Orbital properties
•Ground state electron configuration: [Xe].4f14.6s2
•Shell structure: 2.8.18.32.8.2
•Term symbol: 1S0

Isolation
Ytterbium 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 ytterbium is available through the electrolysis of a mixture of molten YbCl3 and NaCl (or CaCl2) in a graphite cell which acts as cathode using graphite as anode. The other product is chlorine gas.

Thulium (69)

Thulium is the least abundant of the earth elements, and is about as rare as silver, gold, or cadmium.

The pure metal has a bright, silvery lustre. It is reasonably stable in air, but the metal must be protected from moisture. The element is silvery-grey, soft, malleable, and ductile, and can be cut with a knife. It is a rare earth metal found in minerals such as monazite.

•Name: Thulium
•Symbol: Tm
•Atomic number: 69
•Atomic weight: 168.93421 (2) 
•Standard state: solid at 298 K
•CAS Registry ID: 7440-30-4
•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
Thulium was discovered by Per Theodore Cleve at 1879 in Sweden, while working on erbia earth (erbium oxide). Origin of name: named after ""Thule", an ancient name for Scandinavia. Thulium oxide (holmia) was present as an impurity in the erbia. The element is named after Thule, the ancient name for Scandinavia. 

Physical properties 
•Melting point: 1818 [or 1545 °C (2813 °F)] K
•Boiling point: 2223 [or 1950 °C (3542 °F)] K
•Density of solid: 9321 kg m-3

Orbital properties
•Ground state electron configuration: [Xe].4f13.6s2
•Shell structure: 2.8.18.31.8.2
•Term symbol: 2F7/2

Isolation
Thulium 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 thulium is available through the reduction of TmF3 with calcium metal.

2TmF3 + 3Ca → 2Tm + 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.

 

Erbium (68)

It has recently been brought to my attention (read, TODAY) that i left out an element of the Lanthanide series. Ladies and gentlemen, I give you:

ERBIUM

Pure erbium metal is soft and malleable and has a bright, silvery, metallic luster. As with other rare-earth metals, its properties depend to a certain extent on impurities present. The metal is fairly stable in air and does not oxidize as rapidly as some of the other rare-earth metals.

Erbium

Symbol: Er

Atomic number: 68

Atomic weight: 167.259 (3) [see note g]

Standard state: solid at 298 K

CAS Registry ID: 7440-52-0

Group name: Lanthanoid

Period in periodic table: 6 (lanthanoid)

Block in periodic table: f-block

Color: silvery white

Classification: Metallic

Historical information

Erbium was discovered by Carl G. Mosander at 1842 in Sweden. Origin of name: named after the village of "Ytterby" near Vaxholm in Sweden. 

(this section gets a bit confusing...)

In 1842 Gustav Mosander separated "yttria", found in the mineral gadolinite, into three fractions which he called yttria, erbia, and terbia. The names erbia and terbia became confused in this early period. After 1860, Mosander's terbia was known as erbia, and after 1877, the earlier known erbia became terbia. The erbia of this period was later shown to consist of five oxides, now known as erbia, scandia, holmia, thulia and ytterbia. Klemm and Bommer first produced reasonably pure erbium metal in 1934 by reducing the anhydrous chloride with potassium vapour.

Physical properties

Melting point: 1802 [or 1529 °C (2784 °F)] K

Boiling point: 3141 [or 2868 °C (5194 °F)] K

Density of solid: 9066 kg m-3

Orbital properties

Ground state electron configuration:  [Xe].4f12.6s2

Shell structure:  2.8.18.30.8.2

Isolation

Erbium 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 erbium is available through the reduction of ErF3 with calcium metal.

2ErF3 + 3Ca → 2Er + 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.

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.