FERMIUM, Fm (100)

Fermium was discovered in the debris of the first hydrogen bomb explosion, it is the heaviest element that can be formed by neutron bombardment of lighter elements, and hence the last element that can be prepared in macroscopic quantities, although pure fermium metal has not yet been prepared. A total of 19 isotopes are known, with 257Fm being the longest-lived with a half-life of 100.5 days.

ELEMENT BRIEF

1952 by Workers at Argonne and the University of California at Berkeley, USA.

DISCOVERY

From the name of Enrico Fermi.

ETYMOLOGY

Fermium

ELEMENT

Fm

SYMBOL

100

ATOMIC NUMBER

7440-72-4

CAS NUMBER

ELEMENTAL SPECTRUM

Silver

ELEMENTAL COLOUR

-

REFRACTIVE INDEX

-

POISSON RATIO

26.505 cm³

MOLAR VOLUME

-

BRINELL HARDNESS

-

MOHS HARDNESS

-

VICKERS HARDNESS

-

SPEED OF SOUND

-

BULK MODULUS

-

SHEAR MODULUS

-

YOUNG MODULUS

ALLOTROPES

NONE

1,800.15 K, 1,527.00 °C

MELTING POINT

-

BOILING POINT

-

AUTOMATIC IGNITION

-

FLASHPOINT

-

CRITICAL TEMPERATURE

-

CRITICAL PRESSURE

10.000'000 W/(m K)

THERMAL CONDUCTIVITY

-

THERMAL EXPANSION

-

SPECIFIC HEAT

-

HEAT FUSION

-

HEAT VAPORISATION

-

HEAT COMBUSTION

-

CURIE POINT

-

NEEL POINT

-

ADIABATIC INDEX

Solid

PHASE

-

ELECTRICAL TYPE

-

CONDUCTIVITY

-

RESISTIVITY

0.600 K

SUPERCONDUCTING POINT

-

MAGNETIC TYPE

-

MASS SUSCEPTIBILITY

-

MOLAR SUSCEPTIBILITY

-

VOLUME SUSCEPTIBILITY

Actinide

CLASSIFICATION

257.095'106'1

ATOMIC WEIGHT

-

ATOMIC RADIUS

167 pm

COVALENT RADIUS SINGLE BOND

-

COVALENT RADIUS DOUBLE BOND

-

COVALENT RADIUS TRIPLE BOND

245 pm

VAN DER WAALS RADIUS

[Rn]7s²5f¹²

ELECTRON CONFIGURATION

Cubic, Face-centred

CRYSTAL STRUCTURE

9.700'00 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