mendelevium

See also: Mendelevium, mendelévium, and mendélévium

English

WOTD – 8 February 2026

Chemical element (edit)
Md Atomic number 101 mendelevium
Classification data Period 7 Group 3 Block f-block Class actinide
Previous: ← fermium (Fm)
Next: nobelium (No) →
English Wikipedia article on Mendelevium

Etymology

From a modified version of Mendeleev +‎ -ium (suffix forming names of metal elements), named in honour of the Russian chemist Dmitri Mendeleev (1834–1907) who formulated the periodic law and created an early version of the periodic table of elements. The word was proposed by a team from the University of California, Berkeley, comprising the team leader Stanley Gerald Thompson and members Gregory Robert Choppin, Albert Ghiorso, Bernard George Harvey, and Glenn T. Seaborg, who artificially synthesized the element in early 1955. (The same name was proposed, but rejected, for the earlier-discovered elements berkelium and erbium.)

Pronunciation

• (Received Pronunciation) enPR: mĕndəlēv'ēəm, IPA^(key): /ˌmɛn.dəˈliː.vi.əm/, /-ˈleɪ-/
• (General American) IPA^(key): /ˌmɛn.dəˈli.vi.əm/, /-ˈleɪ-/

• Audio (General American); /ˌmɛn.dəˈli.vi.əm/:

  (file)

  (file)

• Hyphenation: men‧de‧lev‧i‧um

Noun

mendelevium (uncountable)

2. (chemistry) A radioactive metallic transuranic chemical element (symbol Md) with atomic number 101, which is artificially produced in a particle accelerator.

   Synonyms: (symbol) Md, (symbol, obsolete) Mv, (dated) unnilunium

   • 1955 May 14, “Element 101 Discovered”, in Science News Letter, volume 67, number 20, Washington, D.C.: Science Service, →ISSN, →OCLC, page 307, column 1:

     Mendelevium, the heaviest and rarest form of matter known, has been produced in the University of California's cyclotron. Identity based on only 17 atoms of new element [subtitle]. […] Mendelevium is intensely radioactive, decaying by spontaneous fission. Its half-life is between a half hour and three hours. It has chemical properties similar to those of thulium, element 69, a rare earth.

   • 1959 (date composed), Tom Lehrer, “The Elements”, in Too Many Songs, New York, N.Y.: Pantheon Books, published 1981, →ISBN, part 2 (From An Evening Wasted with Tom Lehrer), page 151, column 2:

     There's sulfur, californium, and fermium, berkelium, / And also mendelevium, einsteinium, nobelium, / And argon, krypton, neon, radon, xenon, zinc, and rhodium, / And chlorine, carbon, cobalt, copper, tungsten, tin, and sodium.

   • 1963 January, “Physical Research: New Physical Research Facilities”, in Major Activities in the Atomic Energy Programs: January–December 1962, United States Atomic Energy Commission, United States Government Printing Office, →OCLC, part 4 (Other Major Programs), page 336:

     Seven new elements were discovered with the 60-inch cyclotron: 85 (astatine), 93 (neptunium), 94 (plutonium), 96 (curium), 97 (berkelium), 98 (californium), and 101 (mendeleevium).

   • 1987, R. S. Baghavan, “The Transformation from Quantity to Quality and Quality to Quantity”, in An Introduction to the Philosophy of Marxism, 2nd edition, part I, London: Socialist Platform, →ISBN, page 115:

     In the expert hands of Enrico Fermi, beginning with 1934, neutron bombardment produced new atomic miracles. In 1940, Fermi created neptunium (Z = 93), the first artificial, 'trans-uranic', element. Others, also unstable, soon followed, among them fermium (Z = 100) and mendeleyevium (Z = 101).

     First published as a series of articles in the magazine Young Socialist (Ceylon, 1962–1970).

   • 2025 July, Iain MacGregor, “Notes [to chapter 6]”, in The Hiroshima Men: The Quest to Build the Atomic Bomb, and the Fateful Decision to Use It, 1st Scribner hardcover edition, New York, N.Y.: Scribner, →ISBN, endnote 6, page 381:

     [Glenn Theodore] Seaborg would be the principal co-discoverer of ten elements on the periodic table: plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium, and element 106.

Alternative forms

• mendeleevium, mendeleyevium (rare)

Derived terms

• Md
• mendelevate
• Mv (obsolete)

Related terms

• Mendeleev

Translations

chemical element with atomic number 101

• Afrikaans: mendelevium (af)
• Albanian: mendelevium
• Arabic: مَنْدَلِفْيُوم m (mandalifyum)
• Armenian: մենդելևիում (mendelewium)
• Asturian: mendeleviu (ast) m
• Basque: mendelebioa
• Belarusian: мендзяле́вій m (mjendzjaljévij)
• Breton: mendeleviom (br)
• Bulgarian: менделе́вий (bg) m (mendelévij)
• Catalan: mendelevi (ca)
• Chinese:

  Mandarin: 鍆 / 钔 (zh) (mén)

• Cornish: mendelevyum
• Czech: mendelevium (cs)
• Danish: mendelevium (da) n
• Dutch: mendelevium (nl) n
• Esperanto: mendelevio (eo)
• Estonian: mendeleevium (et)
• Faroese: mendelevium n
• Finnish: mendelevium (fi)
• French: mendélévium (fr) m
• Frisian:

  West Frisian: mendelevium

• Friulian: mendelevi
• Galician: mendelevio (gl)
• Georgian: მენდელეევიუმი (mendeleeviumi)
• German: Mendelevium (de) n
• Greek: μεντελέβιο (el) n (mentelévio)
• Hebrew: מנדלביום (he) (mendelevyum)
• Hungarian: mendelévium (hu)
• Icelandic: mendelevín (is)
• Irish: meindiléiviam
• Italian: mendelevio (it) m
• Japanese: メンデレビウム (ja) (menderebiumu)
• Kashubian: mendeléw
• Kazakh: менделевий (mendelevii)
• Korean: 멘델레븀 (ko) (mendellebyum)
• Latin: mendelelevium
• Latvian: mendelevijs
• Lithuanian: mendelevis (lt)
• Luxembourgish: Mendelevium
• Macedonian: менделевиум m (mendelevium)
• Malay: mendelevium
• Maltese: mendelevjum
• Manx: mendelevium
• Mongolian: менделеби (mendelebi)
• Norwegian: mendelevium
• Polish: mendelew (pl) m
• Portuguese: mendelévio (pt) m
• Romanian: mendeleviu (ro) n
• Russian: менделе́вий (ru) m (mendelévij)
• Scottish Gaelic: meindilèiviam
• Serbo-Croatian: мендељевиj m, мендељевиjум m

  Latin: mendeljevij, mendeljevijum

• Slovak: mendelevium n
• Slovene: mendelevij (sl) m
• Spanish: mendelevio (es) m
• Swedish: mendelevium (sv) n
• Tajik: менделевий (mendeleviy)
• Tamil: மெண்டலேவியம் (meṇṭalēviyam)
• Thai: เมนเดลีเวียม (men-dee-lii-wîiam)
• Turkish: mendelevyum (tr)
• Ukrainian: менделе́вій m (mendelévij)
• Uyghur: مېندېلېيېۋىي (mëndëlëyëwiy)
• Uzbek: mendeleviy, менделеевий (mendeleyeviy)
• Vietnamese: menđelevi
• Volapük: mendelevin (vo)
• Welsh: mendelefiwm

Further reading

• mendelevium on Wikipedia.Wikipedia

Afrikaans

Chemical element (edit)
Md Atomic number 101 mendelevium
Classification data Period 7 Group 3 Block f-block Class actinide
Previous: ← fermium (Fm)
Next: nobelium (No) →

Noun

mendelevium (uncountable)

1. mendelevium

Danish

Chemical element (edit)
Md Atomic number 101 mendelevium
Classification data Period 7 Group 3 Block f-block Class actinide
Previous: ← fermium (Fm)
Next: nobelium (No) →

Etymology

From Russian Менделеев (Mendelejev) +‎ -ium. Named after the scientist Dmitri Mendeleev

Noun

mendelevium n (singular definite mendeleviummet, not used in plural form)

1. mendelevium

Declension

Declension of mendelevium

neuter gender	singular
	indefinite	definite
nominative	mendelevium	mendeleviummet
genitive	mendeleviums	mendeleviummets

References

• “mendelevium” in Den Danske Ordbog

Dutch

Chemical element (edit)
Md Atomic number 101 mendelevium
Classification data Period 7 Group 3 Block f-block Class actinide
Previous: ← fermium (Fm)
Next: nobelium (No) →

Pronunciation

• Audio:

  (file)

Noun

mendelevium n (uncountable, no diminutive)

1. mendelevium

Finnish

Etymology

Internationalism (see English mendelevium).

Pronunciation

• IPA^(key): /ˈmendeleʋium/, [ˈme̞nde̞ˌle̞ʋium]
• Rhymes: -eʋium
• Syllabification^(key): men‧de‧le‧vi‧um
• Hyphenation^(key): men‧de‧le‧vi‧um

Noun

mendelevium

1. mendelevium

Declension

Inflection of mendelevium (Kotus type 5/risti, no gradation)
nominative		mendelevium	mendeleviumit
genitive		mendeleviumin	mendeleviumien
partitive		mendeleviumia	mendeleviumeja
illative		mendeleviumiin	mendeleviumeihin
		singular	plural
nominative		mendelevium	mendeleviumit
accusative	nom.	mendelevium	mendeleviumit
	gen.	mendeleviumin
genitive		mendeleviumin	mendeleviumien
partitive		mendeleviumia	mendeleviumeja
inessive		mendeleviumissa	mendeleviumeissa
elative		mendeleviumista	mendeleviumeista
illative		mendeleviumiin	mendeleviumeihin
adessive		mendeleviumilla	mendeleviumeilla
ablative		mendeleviumilta	mendeleviumeilta
allative		mendeleviumille	mendeleviumeille
essive		mendeleviumina	mendeleviumeina
translative		mendeleviumiksi	mendeleviumeiksi
abessive		mendeleviumitta	mendeleviumeitta
instructive		—	mendeleviumein
comitative		See the possessive forms below.

Possessive forms of mendelevium (Kotus type 5/risti, no gradation)

first-person singular possessor singular plural nominative mendeleviumini mendeleviumini accusative nom. mendeleviumini mendeleviumini gen. mendeleviumini genitive mendeleviumini mendeleviumieni partitive mendeleviumiani mendeleviumejani inessive mendeleviumissani mendeleviumeissani elative mendeleviumistani mendeleviumeistani illative mendeleviumiini mendeleviumeihini adessive mendeleviumillani mendeleviumeillani ablative mendeleviumiltani mendeleviumeiltani allative mendeleviumilleni mendeleviumeilleni essive mendeleviuminani mendeleviumeinani translative mendeleviumikseni mendeleviumeikseni abessive mendeleviumittani mendeleviumeittani instructive — — comitative — mendeleviumeineni second-person singular possessor singular plural nominative mendeleviumisi mendeleviumisi accusative nom. mendeleviumisi mendeleviumisi gen. mendeleviumisi genitive mendeleviumisi mendeleviumiesi partitive mendeleviumiasi mendeleviumejasi inessive mendeleviumissasi mendeleviumeissasi elative mendeleviumistasi mendeleviumeistasi illative mendeleviumiisi mendeleviumeihisi adessive mendeleviumillasi mendeleviumeillasi ablative mendeleviumiltasi mendeleviumeiltasi allative mendeleviumillesi mendeleviumeillesi essive mendeleviuminasi mendeleviumeinasi translative mendeleviumiksesi mendeleviumeiksesi abessive mendeleviumittasi mendeleviumeittasi instructive — — comitative — mendeleviumeinesi first-person plural possessor singular plural nominative mendeleviumimme mendeleviumimme accusative nom. mendeleviumimme mendeleviumimme gen. mendeleviumimme genitive mendeleviumimme mendeleviumiemme partitive mendeleviumiamme mendeleviumejamme inessive mendeleviumissamme mendeleviumeissamme elative mendeleviumistamme mendeleviumeistamme illative mendeleviumiimme mendeleviumeihimme adessive mendeleviumillamme mendeleviumeillamme ablative mendeleviumiltamme mendeleviumeiltamme allative mendeleviumillemme mendeleviumeillemme essive mendeleviuminamme mendeleviumeinamme translative mendeleviumiksemme mendeleviumeiksemme abessive mendeleviumittamme mendeleviumeittamme instructive — — comitative — mendeleviumeinemme second-person plural possessor singular plural nominative mendeleviuminne mendeleviuminne accusative nom. mendeleviuminne mendeleviuminne gen. mendeleviuminne genitive mendeleviuminne mendeleviumienne partitive mendeleviumianne mendeleviumejanne inessive mendeleviumissanne mendeleviumeissanne elative mendeleviumistanne mendeleviumeistanne illative mendeleviumiinne mendeleviumeihinne adessive mendeleviumillanne mendeleviumeillanne ablative mendeleviumiltanne mendeleviumeiltanne allative mendeleviumillenne mendeleviumeillenne essive mendeleviuminanne mendeleviumeinanne translative mendeleviumiksenne mendeleviumeiksenne abessive mendeleviumittanne mendeleviumeittanne instructive — — comitative — mendeleviumeinenne third-person possessor singular plural nominative mendeleviuminsa mendeleviuminsa accusative nom. mendeleviuminsa mendeleviuminsa gen. mendeleviuminsa genitive mendeleviuminsa mendeleviumiensa partitive mendeleviumiaan mendeleviumiansa mendeleviumejaan mendeleviumejansa inessive mendeleviumissaan mendeleviumissansa mendeleviumeissaan mendeleviumeissansa elative mendeleviumistaan mendeleviumistansa mendeleviumeistaan mendeleviumeistansa illative mendeleviumiinsa mendeleviumeihinsa adessive mendeleviumillaan mendeleviumillansa mendeleviumeillaan mendeleviumeillansa ablative mendeleviumiltaan mendeleviumiltansa mendeleviumeiltaan mendeleviumeiltansa allative mendeleviumilleen mendeleviumillensa mendeleviumeilleen mendeleviumeillensa essive mendeleviuminaan mendeleviuminansa mendeleviumeinaan mendeleviumeinansa translative mendeleviumikseen mendeleviumiksensa mendeleviumeikseen mendeleviumeiksensa abessive mendeleviumittaan mendeleviumittansa mendeleviumeittaan mendeleviumeittansa instructive — — comitative — mendeleviumeineen mendeleviumeinensa

Latin

Chemical element (edit)
Md Atomic number 101 mendelevium
Classification data Period 7 Group 3 Block f-block Class actinide
Previous: ← fermium (Fm)
Next: nobelium (No) →

Etymology

Named after Russian chemist and inventor Дми́трий Ива́нович Менделе́ев (Dmítrij Ivánovič Mendeléev) (1834–1907).
Derived from Mendeleev +‎ -ium (chemical element suffix).

Pronunciation

• (Classical Latin) IPA^(key): [mɛn.dɛˈɫeː.wi.ũː]
• (modern Italianate Ecclesiastical) IPA^(key): [men.deˈlɛː.vi.um]

Noun

mendelēvium n (genitive mendelēviī); second declension

1. (New Latin, chemistry) mendelevium

Declension

Second-declension noun (neuter).

	singular	plural
nominative	mendelēvium	mendelēvia
genitive	mendelēviī	mendelēviōrum
dative	mendelēviō	mendelēviīs
accusative	mendelēvium	mendelēvia
ablative	mendelēviō	mendelēviīs
vocative	mendelēvium	mendelēvia

Descendants

• → English: mendelevium
• → Italian: mendelevio

Malay

Chemical element (edit)
Md Atomic number 101 mendelevium
Classification data Period 7 Group 3 Block f-block Class actinide
Previous: ← fermium (Fm)
Next: nobelium (No) →

Etymology

From English mendelevium.

Pronunciation

• IPA^(key): [mɛndəlɛviom], [mɛndəlɛviəm]
• Rhymes: -iom, -jom, -om

Noun

mendelevium

1. mendelevium (chemical element)

Slovak

Pronunciation

• IPA^(key): /ˈmɛndɛlɛvɪjʊm/

Noun

mendelevium n (genitive singular mendelevia, declension pattern of mesto)

1. alternative form of mendelévium: mendelevium (element)

Declension

Declension of mendelevium

	singulare tantum
nominative	mendelevium
genitive	mendelevia
dative	mendeleviu
accusative	mendelevium
locative	mendeleviu
instrumental	mendeleviom

Further reading

• “mendelevium”, in Slovníkový portál Jazykovedného ústavu Ľ. Štúra SAV [Dictionary portal of the Ľ. Štúr Institute of Linguistics, Slovak Academy of Science] (in Slovak), https://slovnik.juls.savba.sk, 2003–2026

Swedish

Chemical element (edit)
Md Atomic number 101 mendelevium
Classification data Period 7 Group 3 Block f-block Class actinide
Previous: ← fermium (Fm)
Next: nobelium (No) →

Noun

mendelevium n

1. mendelevium

Declension

Declension of mendelevium

		nominative	genitive
singular	indefinite	mendelevium	mendeleviums
	definite	mendeleviumet	mendeleviumets
plural	indefinite	—	—
	definite	—	—

Declension of mendelevium

		nominative	genitive
singular	indefinite	mendelevium	mendeleviums
	definite	mendeleviet	mendeleviets
plural	indefinite	—	—
	definite	—	—

Declension of mendelevium

		nominative	genitive
singular	indefinite	mendelevium	mendeleviums
	definite	mendelevium	mendeleviums
plural	indefinite	—	—
	definite	—	—

References

• Svensk MeSH