Editing Rare-earth element (section)

==Elements==
A table listing the 17 rare-earth elements, their [[atomic number]] and symbol, the etymology of their names, and their main uses (see also [[Lanthanide#Applications|Applications of lanthanides]]) is provided here. Some of the rare-earth elements are named after the scientists who discovered them, or elucidated their elemental properties, and some after the geographical locations where discovered.

{| class="wikitable sortable"
|+Overview of rare-earth metal properties
|-
!scope="col"|[[Atomic number|Z]]
!scope="col"|Symbol
!scope="col"|Name
!scope="col" class="unsortable" |Etymology
!scope="col" class="unsortable" |Selected applications
!scope="col" data-sort-type="number" |Abundance<ref>{{cite web |url=https://geology.com/usgs/ree-geology/ |author1=Keith R. Long |author2=Bradley S. Van Gosen |author3=Nora K. Foley |author4=Daniel Cordier |title=The Geology of Rare Earth Elements |website=Geology.com |access-date=2018-06-19 |archive-date=October 26, 2021 |archive-url=https://web.archive.org/web/20211026102954/https://geology.com/usgs/ree-geology/ |url-status=live}}</ref><ref>{{cite book |editor-first=David R. |editor-last=Lide |title=CRC Handbook of Chemistry and Physics |date=1996–1997 |edition=77th |location=Boca Raton, Florida |publisher=CRC Press |isbn=0-8493-0477-6 |pages=10–12}}</ref><br/>(ppm{{efn|group=tab1|1=Parts per million in Earth's crust, e.g. Pb=13 ppm}})
|-
| style="text-align:center;" |21
| style="text-align:center;" |Sc
!scope="row"|[[Scandium]]
|from [[Latin]] ''Scandia'' ([[Scandinavia]]).
|Light [[aluminium-scandium alloy]]s for aerospace components, additive in [[metal-halide lamp]]s and [[mercury-vapor lamp]]s,<ref name="CRC_ed89_elements">{{cite book |author=C. R. Hammond |chapter=Section 4; The Elements |title=CRC Handbook of Chemistry and Physics |edition=89th |others=(Internet Version 2009) |editor=David R. Lide |publisher=CRC Press/Taylor and Francis |location=Boca Raton, FL}}</ref> radioactive tracing agent in oil refineries
| {{0}}22
|-
| style="text-align:center;" |39
| style="text-align:center;" |Y
!scope="row"|[[Yttrium]]
|after the village of [[Ytterby|Ytterby, Sweden]], where the first rare-earth ore was discovered.
|[[Yttrium aluminium garnet]] (YAG) laser, yttrium vanadate (YVO{{sub|4}}) as host for europium in television red phosphor, [[yttrium barium copper oxide|YBCO]] [[High-temperature superconductivity|high-temperature superconductors]], [[yttria-stabilized zirconia]] (YSZ) (used in [[tooth crowns]]; as refractory material - in metal alloys used in jet engines, and coatings of engines and industrial gas turbines; [[electroceramic]]s - for measuring oxygen and pH of hot water solutions, i.e. in fuel cells; ceramic electrolyte - used in [[solid oxide fuel cell]]; jewelry - for its hardness and optical properties; do-it-yourself high temperature ceramics and cements based on water), [[yttrium iron garnet]] (YIG) [[microwave]] filters,<ref name="CRC_ed89_elements"/> energy-efficient light bulbs (part of triphosphor white phosphor coating in fluorescent tubes, CFLs and CCFLs, and yellow phosphor coating in white LEDs),<ref>{{cite web |website=Think GlobalGreen |url=http://www.thinkglobalgreen.org/rare-earthmetals.html |title=Rare-earth metals |access-date=10 February 2017 |archive-url=https://web.archive.org/web/20161104194856/http://www.thinkglobalgreen.org/rare-earthmetals.html |archive-date=2016-11-04}}</ref> [[spark plug]]s, gas mantles, additive to steel, aluminium and magnesium alloys, [[cancer treatments]], camera and [[refractive telescope]] lenses (due to high refractive index and very low thermal expansion), battery cathodes (LYP)
| {{0}}33
|-
| style="text-align:center;" |57
| style="text-align:center;" |La
!scope="row"|[[Lanthanum]]
|from the Greek "lanthanein", meaning ''to be hidden''.
|High [[refractive index]] and alkali-resistant glass, flint, hydrogen storage, battery-electrodes, [[camera]] and [[refractive telescope]] lenses, [[fluid catalytic cracking]] catalyst for oil refineries
| {{0}}39
|-
| style="text-align:center;" |58
| style="text-align:center;" |Ce
!scope="row"|[[Cerium]]
|after the dwarf planet [[Ceres (dwarf planet)|Ceres]], named after [[Ceres (mythology)|the Roman goddess of agriculture]].
|Chemical [[oxidizing agent]], polishing powder, yellow colors in glass and ceramics, catalyst for [[self-cleaning oven]]s, [[fluid catalytic cracking]] catalyst for oil refineries, [[ferrocerium]] flints for lighters, robust intrinsically [[hydrophobic]] coatings for turbine blades<ref>{{cite journal |last1=Fronzi |first1=M |title=Theoretical insights into the hydrophobicity of low index CeO<sub>2</sub> surfaces |journal=Applied Surface Science |year=2019 |volume=478 |pages=68–74 |doi=10.1016/j.apsusc.2019.01.208 |arxiv=1902.02662 |url=https://hal.archives-ouvertes.fr/hal-02308396/document |bibcode=2019ApSS..478...68F |s2cid=118895100 |access-date=February 9, 2021 |archive-date=April 10, 2022 |archive-url=https://web.archive.org/web/20220410095114/https://hal.archives-ouvertes.fr/hal-02308396/document |url-status=live}}</ref>
| {{0}}66.5
|-
| style="text-align:center;" |59
| style="text-align:center;" |Pr
!scope="row"|[[Praseodymium]]
|from the Greek "prasios", meaning ''leek-green'', and "didymos", meaning ''twin''.
|[[Rare-earth magnet]]s, [[laser]]s, core material for [[carbon arc]] lighting, colorant in [[glass]]es and [[Vitreous enamel|enamel]]s, additive in [[didymium]] glass used in [[welding goggles]],<ref name="CRC_ed89_elements"/> [[ferrocerium]] firesteel (flint) products, single-mode fiber optical amplifiers (as a dopant of [[fluoride glass]])
| {{0|00}}9.2
|-
| style="text-align:center;" |60
| style="text-align:center;" |Nd
!scope="row"|[[Neodymium]]
|from the Greek "neos", meaning ''new'', and "didymos", meaning ''twin''.
|[[Rare-earth magnet]]s, [[laser]]s, violet colors in glass and ceramics, [[didymium]] glass, [[ceramic capacitor]]s, electric motors in electric automobiles
| {{0}}41.5
|-
| style="text-align:center;" |61
| style="text-align:center;" |Pm
!scope="row"|[[Promethium]]
|after the [[Titan (mythology)|Titan]] [[Prometheus]], who brought fire to mortals.
|[[Atomic battery|Nuclear batteries]], [[luminous paint]]
| data-sort-value="0" |{{0}}{{val|1e-15}}<ref>{{cite book |title=Ullmann's Encyclopedia of Industrial Chemistry |volume=31 |editor=Fritz Ullmann |others=Contributor: Matthias Bohnet |edition=6th |publisher=Wiley-VCH |year=2003 |isbn=978-3-527-30385-4 |page=24}}</ref>{{efn|group=tab1|1=Promethium has no [[stable isotope]]s or [[primordial radioisotope]]s; trace quantities occur in nature as [[fission product]]s.}}
|-
| style="text-align:center;" |62
| style="text-align:center;" |Sm
!scope="row"|[[Samarium]]
|after mine official, [[Vasili Samarsky-Bykhovets]].
|[[Rare-earth magnet]]s, [[laser]]s, [[neutron capture]], [[maser]]s, [[control rod]]s of [[nuclear reactor]]s
| {{0|00}}7.05
|-
| style="text-align:center;" |63
| style="text-align:center;" |Eu
!scope="row"|[[Europium]]
|after the continent of [[Europe]].
|Red and blue [[phosphor]]s, [[laser]]s, [[mercury-vapor lamp]]s, [[fluorescent lamp]]s, [[NMR]] [[relaxation (NMR)|relaxation agent]]
| {{0|00}}2
|-
| style="text-align:center;" |64
| style="text-align:center;" |Gd
!scope="row"|[[Gadolinium]]
|after [[Johan Gadolin]] (1760–1852), to honor his investigation of rare earths.
|High refractive index glass or [[garnet]]s, [[laser]]s, [[X-ray tube]]s, [[bubble memory|computer bubble memories]], [[neutron capture]], [[MRI contrast agent]], [[relaxation (NMR)|NMR relaxation agent]], steel and chromium alloys additive, [[magnetic refrigeration]] (using significant [[magnetocaloric effect]]), [[positron emission tomography]] [[scintillator]] detectors, a substrate for magneto-optical films, high performance [[high-temperature superconductor]]s, [[ceramic electrolyte]] used in [[solid oxide fuel cell]]s, [[oxygen]] detectors, possibly in catalytic conversion of automobile fumes.
| {{0|00}}6.2
|-
| style="text-align:center;" |65
| style="text-align:center;" |Tb
!scope="row"|[[Terbium]]
|after the village of [[Ytterby]], [[Sweden]].
|Additive in [[Neodymium magnet|neodymium based magnets]], green [[phosphor]]s, [[laser]]s, [[fluorescent lamp]]s (as part of the white triband phosphor coating), [[Magnetostriction|magnetostrictive alloys]] such as [[terfenol-D]], naval [[sonar]] systems, stabilizer of [[fuel cells]]
| {{0|00}}1.2
|-
| style="text-align:center;" |66
| style="text-align:center;" |Dy
!scope="row"|[[Dysprosium]]
|from the Greek "dysprositos", meaning ''hard to get''.
|Additive in [[neodymium magnet|neodymium based magnets]], [[laser]]s, [[magnetostriction|magnetostrictive alloys]] such as [[terfenol-D]], [[hard disk drives]]
| {{0|00}}5.2
|-
| style="text-align:center;" |67
| style="text-align:center;" |Ho
!scope="row"|[[Holmium]]
|after [[Stockholm]] (in Latin, "Holmia"), the native city of one of its discoverers.
|[[Laser]]s, wavelength calibration standards for optical [[spectrophotometry|spectrophotometer]]s, [[magnet]]s
| {{0|00}}1.3
|-
| style="text-align:center;" |68
| style="text-align:center;" |Er
!scope="row"|[[Erbium]]
|after the village of Ytterby, Sweden.
|Infrared [[laser]]s, [[vanadium steel]], [[optical fiber|fiber-optic]] technology
| {{0|00}}3.5
|-
| style="text-align:center;" |69
| style="text-align:center;" |Tm
!scope="row"|[[Thulium]]
|after the mythological northern land of [[Thule]].
|Portable [[X-ray machine]]s, [[metal-halide lamp]]s, [[laser]]s
| {{0|00}}0.52
|-
| style="text-align:center;" |70
| style="text-align:center;" |Yb
!scope="row"|[[Ytterbium]]
|after the village of Ytterby, Sweden.
|Infrared [[laser]]s, chemical [[reducing agent]], [[flare (countermeasure)|decoy flares]], [[stainless steel]], [[strain gauge]]s, [[nuclear medicine]], [[earthquake]] monitoring
| {{0|00}}3.2
|-
| style="text-align:center;" |71
| style="text-align:center;" |Lu
!scope="row"|[[Lutetium]]
|after [[Lutetia]], the city that later became [[Paris]].
|[[Positron emission tomography]] – PET scan detectors, high-refractive-index glass, [[lutetium tantalate]] hosts for phosphors, catalyst used in [[oil refinery|refineries]], [[LED light bulb]]
| {{0|00}}0.8
|}
{{notelist|group=tab1}}

A mnemonic for the names of the sixth-row elements in order is "Lately college parties never produce sexy European girls that drink heavily even though you look".<ref>Mentioned by Prof. [[Andrea Sella]] on a BBC [[Business Daily]] programme, March 19, 2014 [http://www.bbc.co.uk/podcasts/series/elements]. Unfortunately this mnemonic doesn't distinguish very well between praseodymium and promethium and between terbium and thulium.</ref>