MENDELEVIUM, Md (101)

Mendelevium is a metallic radioactive transuranic element and is the first element that currently cannot be produced in macroscopic quantities through neutron bombardment of lighter elements. 16 isotopes are known, the most stable being 258Md with a half-life of 51 days; nevertheless, the shorter-lived 256Md (half-life 1.27 hours) is most commonly used in chemistry because it can be produced on a larger scale. Discovered by bombarding einsteinium with alpha particles, the same method still used to produce it today. Using available microgram quantities of the isotope einsteinium-253, over a million mendelevium atoms may be produced each hour.

ELEMENT BRIEF

1955 by Glenn T. Seaborg, Albert Ghiorso, Bernard Harvey, Gregory Choppin and Stanley G. Thompson, USA.

DISCOVERY

From the name of Dimitri Mendeleev, Chemist, who greatly contributed to the periodic table.

ETYMOLOGY

Mendelevium

ELEMENT

Md

SYMBOL

101

ATOMIC NUMBER

7440-11-1

CAS NUMBER

ELEMENTAL SPECTRUM

Silver

ELEMENTAL COLOUR

-

REFRACTIVE INDEX

-

POISSON RATIO

25.155 cm³

MOLAR VOLUME

-

BRINELL HARDNESS

-

MOHS HARDNESS

-

VICKERS HARDNESS

-

SPEED OF SOUND

-

BULK MODULUS

-

SHEAR MODULUS

-

YOUNG MODULUS

ALLOTROPES

NONE

1,100.15 K, 827.00 °C

MELTING POINT

-

BOILING POINT

-

AUTOMATIC IGNITION

-

FLASHPOINT

-

CRITICAL TEMPERATURE

-

CRITICAL PRESSURE

-

THERMAL CONDUCTIVITY

-

THERMAL EXPANSION

-

SPECIFIC HEAT

-

HEAT FUSION

-

HEAT VAPORISATION

-

HEAT COMBUSTION

-

CURIE POINT

-

NEEL POINT

-

ADIABATIC INDEX

Solid

PHASE

-

ELECTRICAL TYPE

-

CONDUCTIVITY

-

RESISTIVITY

=

SUPERCONDUCTING POINT

-

MAGNETIC TYPE

-

MASS SUSCEPTIBILITY

-

MOLAR SUSCEPTIBILITY

-

VOLUME SUSCEPTIBILITY

Actinide

CLASSIFICATION

259.101'040'8

ATOMIC WEIGHT

173 pm

ATOMIC RADIUS

139 pm

COVALENT RADIUS SINGLE BOND

-

COVALENT RADIUS DOUBLE BOND

-

COVALENT RADIUS TRIPLE BOND

246 pm

VAN DER WAALS RADIUS

[Rn]7s²5f¹³

ELECTRON CONFIGURATION

Cubic, Face-centred

CRYSTAL STRUCTURE

10.300'00 g/cm³

DENSITY AS SOLID

-

DENSITY AS LIQUID

-

DENSITY AS GAS

-

SPACE GROUP NAME

-

SPACE GROUP NUMBER

-

LATTICE ANGLES

-

LATTICE CONSTANTS

3

VALENCE

1.3

ELECTRONEGATIVITY

-

ELECTRON AFFINITY

IONISATION ENERGY