Holmium

Holmium
General Info
Atomic Symbol	Atomic symbol::Ho
Atomic Number	Atomic number::67
Atomic Weight	Atomic weight::164.93032 g/mol
Chemical series	Lanthanide
Appearance	Silvery White
Group, Period, Block	n/a,6,f
Electron configuration	[Xe] 4f11, 6s2
Electrons per shell	2, 8, 18, 29, 8, 2
CAS number	CAS number::7440-60-0
Physical properties
Phase	Solid
Density	Density::8.54 g/ml
Melting point	Melting point::1470°C
Boiling point	Boiling point::2720°C
Isotopes of Holmium
iso NA half-life DT DE (MeV) DP 163Ho syn 4570 yr ε 0.003 163Dy 164Ho syn 29 min ε 0.987 164Dy 165Ho 100% 165Ho is stable with 98 neutrons. 166Ho syn 26.763 h β− 1.855 66Er 167Ho syn 3.1 h β− 1.007 167Er
All properties are for STP unless otherwise stated.

Holmium is a rare earth element that has the symbol Ho and atomic number 67. A chemist named Per Teoder Cleve discovered this element in 1879 and he named it after his birthplace, Stockholm. This element belongs to the lanthanide series. Holmium is very soft and malleable. The color of holmium is silver. It is reactive when in moist air. Holmium is found in minerals, such as gadolinite and monazite. It is difficult to isolate holmium from other elements because of the similarity of it to other rare earth elements. Due to the characteristics of holmium, it can be used for nuclear control rods. This element also can be used for lasers to treat people's illness. Holmium is not toxic in an appreciable quantity.

Properties

Physical Properties of Holmium

Holmium has magnetic and electrical properties.The melting point of holmium is 2,680°F (1,470°C) and the boiling point is 4,930°F (2,720°C). The density of holmium is 8.803 grams per cubic centimeter. Softness and pliability are the major characteristics of holmium. Holmium usually stays solid in dry air but it rapidly combines with oxygen in moist air.

One of the compounds of holmium (holmium oxide) has unusual color changes. In typical lighting conditions such as during the day, it becomes a tanned yellow color. When this compound goes under trichromatic light, it becomes a fiery orange red. People cannot distinguish it from erbium oxide under this light.

Holmium seems to have the highest magnetic strength (10.6 µB). So when holmium is mixed with yttrium, it will form a strongly magnetic compound.

This element seems to have a low toxicity. It means it usually does not affect or harm. Holmium also does not play any biological roles in humans. However, it might affect metabolism .

Holmium(III) ion

Chemical Properties of Holmium

Holmium usually stays uncorroded in dry air but it starts to become more reactive in moist air and at high temperatures. It combines rapidly with oxygen under either of these conditions. Just like other elements, holmium also can react with other elements that make compounds.

Compounds

Holmium(III) oxide, also known as holmium oxide, is made by reacting holmium with oxygen. Holmium oxide is well known for its use in powerful paramagnetic substances with dysprosium(III) oxide (Dy₂O₃). It is similar to erbium oxide. Special methods are necessary to separate these components. This compound is usually used to make colored glasses. Here is the reaction between holmium and oxygen.

4Ho + 3O₂ → 2Ho₂O₃

Holmium hydroxide is made when holmium reacts with hot water.

2Ho_(s) + 6H₂O_(l) → 2Ho(OH)_3(s) + 3H_2(g)

Holmium reacts with the halogens to make holmium(III) halides. Holmium(III) fluoride is created when holmium and fluorine react. It is a pink solid.

2Ho_(s) + 3F_2(g) → 2HoF_3(s)

Holmium(III) chloride is produced when holmium and chlorine react. This compound changes colors in a similar way to holmium oxide. It is a yellow solid in normal light.

2Ho_(s) + 3Cl_2(g) → 2HoCl_3(s)

Holmium(III) bromide is created when holmium and bromine react. It is a yellow solid.

2Ho_(s) + 3Br_2(g) → 2HoBr_3(s)

Holmium(III) iodide is created when holmium and iodine meet. It is a yellow solid.

2Ho_(s) + 3I_2(g) → 2HoI_3(s)

Holmium reacts with dilute sulfuric acid to make the holmium(III) ion, along with hydrogen gas.

2Ho_(s) + 3H₂SO_4(aq) → 2Ho³⁺(aq) + 3SO₄^2-(aq) + 3H_2(g)

Occurrences

Gadiolinite, a rare earth element ore

Usually, the rare-earth elements are low in concentration and widely distributed throughout the earth's crust. The rare-earth elements also can be found in several minerals. However, they are usually mixed. Holmium is usually found naturally as a pure form. It usually is found on minerals as monazite and gadolinite. The abundance of holmium is twice the abundance of silver. However, the amount of holmium is less than other rare-earth elements. The total amount of holmium is around 0.7 to 1.2 parts per million. People usually obtain holmium in United States, China, India, Brazil, Sri Lanka, and Australia. People gain holmium for commercial purpose from monazite sand but it is very hard to take it from other rare-earth elements. Price of holmium is inexpensive for a rare-earth element. It is usually $1000 per kg in US.

Isolation

Holmium is usually not required to make it in the laboratory because it is commercially available. This means that it is hard to separate it as the pure metal. This happens because the way of holmium is found in nature. Holmium is usually found in the minerals such as xenotime, monazite, and bastnaesite. Xenotime and monazite are orthophosphate(LnPo₄) minerals and bastnaesite is a fluoride carbobate(LnCO₃F). Lanthanoids are more common if they have an even atomic numbers. Cerium is the most common lanthanoids in those minerals and lanthanum, neodymium, and praseodymium are the next.Not many people separate holmium because it is actually unnecessary. However, if people try to separate holmium into individual metals, it is very complicated. Firstly, people have to take the salt from the ores with hydrochloric acid (HCl), sodium hydroxide (NaOH), and sulphuric acid (H₂SO₄). There are modern isolation techniques and they are very ingenious and complicated. People can obtain pure holmium through reduction of HoF₃ with calcium metal shown below.

• 2HoF₃ + 3Ca → 2Ho + 3CaF₂

Uses

Holmium has magnetic properties and this characteristic makes holmium useful to produce the strongest artificially- generated magnetic fields, if it is placed within high-strength magnets as a magenetic fields. Holmium is able to get the nuclear fission- bred neutrons. It also can be used in nucelar control rods. When people produce glasses, they can use the holmium to make yellow-colored glasses.
Nowadays, new technology has been developed that people invented a holmium laser to treat patients. There are many kinds of lasers that can treat many kinds of disease. There is a laser called infrared holmium YAG laser. The purpose of this laser is as in a refractive surgery procedure named laser thermal keratoplasty (LTK). It will try to treat cases of farsightedness and some astigmatism. Holmium laser is not like excimer laser because it creates infrared light that shapes the cornea by causing tissue to constrict whereas other lasers shapes the cornea by getting rid of tissues. Holmium produces a pattern of 8 to 16 small beams in rings around the periphery of the cornea with computer- controlled technique. When the laser hits the cornea, it produces several tiny craters. This way will make center of the cornea to bump and treat the farsightedness.
Moreover, there is another laser of holmium. This laser is called holmium laser for BPH. The purpose of this holmium laser is to get rid of obstructing prostate tissue. It will immediately give symptoms of relief and people will have quality if life with less risk. This laser works with a thin flexible fiver send the energy of laser to prostate precisely.
Lastly, holmium laser can be used for removing kidney stones. The name of this laser is Laser lithotripsy. This laser will make procedures more effective and easier. Usually, this laser is mounted on the end of scope. This scope goes into patient's body. It means that this scope will go through the urethra and bladder. When the scope reaches to the stone, the laser will be turned on and remove the stone.
As many applications are listed, there are more usages of holmium. They are very useful and they can help people for many ways.

Discovery of Holmium

Per Theodor Cleve

There are many people who try to identify holmium. This means many people attempted, but only few people were credited. Firstly, Carl Axel Arrhenius, a lieutenant swedish army, discovered a rock while he was examining a mine that is located at Ytterby in Sweden. Since he was a rock hound, which means a person who likes to study minerals and rocks, decided to examine the rock that he found. He took that rock to Johan Gadolin, Arrhenius' s friend who is a chemistry professor from the university of Abo in Finland. Gadolin actually gave the name ytterite to the rock. Chemists found ytterite very interesting because there are a number of different naturally occurring compounds (once called "earths") in the mineral. Chemist finally discovered that all the compounds in ytterite shows similarity. Because of unusual characteristics of ytterite, chemists took more than a century to observe it.Marc Delafontanie and Jacques- Louis Soret also attempted to figure out the identity of this element. They both are Swiss chemists. In 1878, they discovered this element using the spectroscopic observation. In 1879, a chemist named Per Teodor Cleve was observing a compound named erbia which is from yttria. Other chemists considered erbia as a new element. However, Cleve divided erbia into three parts and named them as erbia, holmia, and thulia. Holmia is the earth of holmium and Cleve finally discovered hoimium. Latin name for holmium is Holmium Stockholm and Cleve named it after his birthplace.

Isotopes

Isotopes are two or more forms of an element. The number of protons determine the name of the element, but the amount of neutrons in the atom always can be different. These variations are called isotopes, and are identified by placing the mass number to the right of the element's name. There is only one naturally occurring isotope of holmium, which is holmium 165. 163 is the most stable holmium. There are minimum 20 radioactive isotopes of holmium. Definition of a radioactive isotope is that something that breaks apart. If small particles are fired at atoms, that's when radioactive isotopes are created. These small particles usually stay in the atoms and make them to become radioactive. Some radioactive isotopes's half lives are no bigger than 1.117 days and they usually have half lives less than 3 hours. Due to high spin, 166m1 has a half life about 1200 years. These isotope becomes very helpful in nuclear physics experiments for adjusting energy responses.

Isotope	Atomic Mass	Half-life
Ho 140	139.96854	6 ms
Ho 141	140.96310	4.1ms
Ho 142	141.95977	400 ms
Ho 143	142.95461	~300 ms
Ho 144	143.95148	0.7 seconds
Ho 145	144.94720	2.4 seconds
Ho 146	145.94464	3.6 seconds
Ho 147	146.94006	5.8 seconds
Ho 148	147.93772	2.2 seconds
Ho 148m1		9.49 seconds
Ho 149	148.933775	21.1 seconds
Ho 149m1		56 seconds
Ho 150	149.933496	76.8 seconds
Ho 150m1		23.2 seconds
Ho 151	150.931688	35.2 seconds
Ho 151m		47.2 seconds
Ho 152	151.931714	161.8 seconds
Ho 152m1		50 seconds
Ho 153	152.930199	2.01 minutes
Ho 153m1		9.3 minutes
Ho 154	153.930602	11.76 minutes
Ho 154m		3.10 minutes
Ho 155	154.929103	48 minutes
Ho 156	155.92984	56 minutes
Ho 156m1		7.8 minutes
Ho 156m2		9.5 seconds
Ho 157	156.928256	12.6 seconds
Ho 158	157.928941	11.3 minutes
Ho 158m1		28 minutes
Ho 158m2		21.3 minutes
Ho 159	158.927712	33.05 minutes
Ho 159m		8.30 seconds
Ho 160	159.928729	25.6 minutes
Ho 160m1		5.02 hours
Ho 160m2		3 seconds
Ho 161m		6.76 seconds
Ho 162	161.929094	15.0 minutes
Ho 162m		67.0 minutes
Ho 163	162.9287339	4570 years
Ho 163m		1.09 seconds
Ho 164	163.9302335	29 minutes
Ho 164m		38.0 minutes
Ho 165	164.9303221	Stable
Ho 166	165.9322842	26.83 hours
Ho 166m1		1.20 X 103 years
Ho 167	166.933133	3.003 hours
Ho 168	167.93552	2.99 minutes
Ho 168m1		132 seconds
Ho 169	168.936872	4.72 minutes
Ho 170	169.93962	2.76 minutes
Ho 170m		43 seconds
Ho 171	170.94147	53 seconds
Ho 172	171.94482	25 seconds
Ho 173	172.94729	~10 seconds
Ho 174	173.95115	~8 seconds
Ho 175	174.95405	~5 seconds

Name of Holmium in different languages

• Afrikaans:Holmium
• Albanian:Holmium
• Armenian:Հոլմիում
• Arabic:هولميوم
• Aromanian: Holmiumu
• Basque:Holmioa
• Bosnian:Holmij
• Breton:Holmio
• Bulgarian:Холъмий
• Byelorussian:Гольмій
• Catalan:Holmi
• Chinese:钬
• Cornish;Holmyum
• Esperanto:Holmio
• French: Holmium
• Galician:Holmio
• Georgian:ჰოლმიუმი
• German:Holmium
• Greek:Όλμιο
• Hebrew:הולמיום
• Irish Gaelic:Hoilmiam
• Italian:Olmio
• Japanese:ホルミウム
• Kashubian:Hòlm
• Kazakh:Голъмий
• Korean:홀뮴
• Latvian:Holmijs
• Lithuanian:Holmis