Per Teodor Cleve Swedish chemist discovered two elements Holmium, Thulium

Per Teodor Cleve – discoverer of Holmium & Thulium elements

Article on Per Teodor Cleve

Biography & contributions

Per Teodor Cleve, a Swedish chemist and geologist had born on February 10, 1840 – June 18, 1905. Cleve was the discoverer of holmium and thulium periodic table elements.

Cleve theorized in 1874 that the element didymium consisted of Neodymium, Praseodymium elements. Cleve proved that the newly discovered element scandium was an element predicted by Dmitri Mendeleev to be "eka-boron". Cleve discovered the element holmium in 1879 from erbium oxide.

While removing impurities from a sample of erbium oxide, Cleve discovered a brown substance and a green substance, and the brown substance was holmium oxide. Cleve separated thulium from an erbium oxide sample in 1879.

Cleve, in collaboration with Hoglund prepared numerous salts of yttrium and erbium. Cleve discovered that thorium was a quadrivalent element and also determined lanthanum to be trivalent. Cleve was the first observer of isomerism in platinumamine derivatives.

He discovered 6 of the 10 possible forms of dichloro naphthalene and the discovery of the aminonaphthalenesulfonic acids, sometimes known as Cleve’s acids.

Facts about holmium

The element name holmium comes from the Greek word ‘Holmia’ meaning Stockholm. Holmium occurs in gadolinite, monazite and in other rare earth minerals.It has been isolated by the reduction of its anhydrous chloride or fluoride with calcium metal. Holmium is a bright, soft, silvery-white, rare earth metal that is both ductile and malleable.

It does not react in dry air at normal temperatures, but rapidly oxidizes to a yellow oxide (Ho2O3) in moist air or when heated. Holmium is also used in solid-state lasers for non-invasive medical procedures treating cancers and kidney stones.

Holmium has the greatest number of impaired electrons and impaired electrons are what give rise to magnetism. Holmium alloys are used as a magnetic flux concentrator to create the strongest artificially-generated magnetic fields. It is also used in nuclear reactors for nuclear control rods. Holmium oxide is used as yellow gas coloring.

Facts about thulium

Thulium is the second least abundant of the lanthanides. Thulium is the least abundant of the naturally occurring rare earth elements. It is an easily workable metal with a bright silvery-gray luster. It is fairly soft and slowly tarnishes in air. Thulium is often found with minerals containing yttrium and gadolinium. Thulium makes up approximately 0.5 parts per million of soil, makes up 250 parts per quadrillion of seawater. Thulium is used as the radiation source in portable X-ray devices and in solid-state lasers.

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