Holmium

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.

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.



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) + 3H2(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) + 3F2(g) → 2HoF3(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) + 3Cl2(g) → 2HoCl3(s)

Holmium(III) bromide is created when holmium and bromine react. It is a yellow solid.
 * 2Ho(s) + 3Br2(g) → 2HoBr3(s)

Holmium(III) iodide is created when holmium and iodine meet. It is a yellow solid.
 * 2Ho(s) + 3I2(g) → 2HoI3(s)

Holmium reacts with dilute sulfuric acid to make the holmium(III) ion, along with hydrogen gas.
 * 2Ho(s) + 3H2SO4(aq) → 2Ho3+(aq) + 3SO42-(aq) + 3H2(g)

Occurrences
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
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.

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

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