Mendelevium

Images

Animated Mendelevium

History

Mendelevium is named after Dmitri Mendeleev. It is the ninth transuranium element of the actinide series discovered. It was first identified by Ghiorso, Harvey, Choppin, Thompson, and Seaborg in early in 1955 during the bombardment of the isotope 253Es with helium ions in the Berkeley 60-inch cyclotron. The isotope produced was 256Md, which has a half-life of 76 min. This first identification was notable in that 256Md was synthesized on a one-atom-at-a-time basis.

Uses

256Md has been used to elucidate some of the chemical properties of mendelevium in aqueous solution.

Isotopes

Fourteen isotopes are now recognized. 258Md has a half-life of 2 months. This isotope has been produced by the bombardment of an isotope of einsteinium with ions of helium. Eventually enough 258Md should be made to determine its physical properties.

General Info

AtomicNumber
101
Symbol
Md
Name
Mendelevium

Atomic Info

Appearance
AtomicWeight
[258]
Color
B30DA6
ElectronicConfiguration
[Rn] 5f13 7s2
ElectronegativityInPauling
1.3
AtomicRadiusInPM
IonRadiusInPM
VanDerWaalsRadiusInPM
IEinKJmol
635
EAinKJmol
OxidationStates
2, 3
StandardState
BondingType
MeltingPoint
1100
BoilingPoint
0
Density
0
State
Actinide
DiscoveredYear
1955