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Mendelevium
Md 101

Mendelevium

Mendelevium is a synthetic chemical element; it has symbol Md (formerly Mv) and atomic number 101. A metallic radioactive transuranium element in the actinide series, it is the first element that currently cannot be produced in macroscopic quantities through neutron bombardment of lighter elements. It was first synthesized in 1955 by Albert Ghiorso, Bernard Harvey, Gregory Choppin, Stanley Thompson, and Glenn T. Seaborg. Mendelevium was named in honor of Dmitri Mendeleev. It has no practical applications outside of scientific research.

Actinide b30da6
Atomic number 101Z
Atomic mass 258u
Valence e⁻ 2
Electron config. 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f13
Density
—
Melting point
827°C
Crustal abundance
—
Annual production
—
Recycling rate
0%(Radioactive synthetic element; no recycling)

Why This Element

Mendelevium is synthesized one atom at a time — all production targets yield fewer than 10 atoms per experiment. No stable isotopes; longest-lived Md-258 has 51.5-day half-life. No commercial applications — studied exclusively for fundamental actinide chain behavior.

Applications

Research

Applications in DepthElement & compound uses

Main Uses of the Element

Mendelevium is the actinide element with atomic number 101, first synthesized in 1955 by a Berkeley team that bombarded an einsteinium target in a cyclotron; it was the first element ever produced one atom at a time. All of its isotopes have half-lives below the minute scale, it does not occur in nature, and it has no industrial or civilian uses; it is currently studied only to investigate the nuclear-synthesis pathways and chemical properties of elements beyond mendelevium.

Key Compounds and Their Uses

Mendelevium compounds have never been prepared in macroscopic quantities. Their oxidation states and coordination behavior have only been inferred from single-atom on-line experiments using solvent extraction and chromatography; no weighable, useful mendelevium compound has ever been formed, and none enters any commercial product or industrial process.

Element History

Discovered in 1955 at UC Berkeley by Seaborg, Ghiorso, Harvey, Thompson, and Choppin — mendelevium-256 was produced bombarding Es-253 with alpha particles, with only 5 atoms detected. Named for Dmitri Mendeleev, creator of the periodic table. Isolated as pure metal in 1978.

Related Elements

Ac · Actinium Th · Thorium Pa · Protactinium U · Uranium Np · Neptunium Pu · Plutonium Am · Americium Cm · Curium

Frequently Asked QuestionsLong-tail Q&A · data-driven

What is the melting point of Mendelevium?
827 °C
What is the boiling point of Mendelevium?
0 °C
What is the density of Mendelevium?
0.0 g/cm³
What are the atomic number and category of Mendelevium?
101 · Actinide
Which ore is Mendelevium mainly extracted from?
None (synthetic)
What are the main uses of Mendelevium?
Mendelevium is synthesized one atom at a time — all production targets yield fewer than 10 atoms per experiment. No stable isotopes; longest-lived Md-258 has 51.5-day half-life. No commercial applications — studied exclu
Who discovered Mendelevium and when?
Lawrence Berkeley National Laboratory · 1955