BERKELIUM, Bk (97)

Berkelium is a transuranic radioactive chemical element with the major isotope 249Bk, synthesised in dedicated high-flux nuclear reactors. The production of the second-important isotope 247Bk involves the irradiation of the rare isotope 244Cm with high-energy alpha particles.

ELEMENT BRIEF

1949 by Glenn T. Seaborg, Stanley G. Thompson and Albert Ghiorso, USA.

DISCOVERY

From the name Berkeley, California, USA.

ETYMOLOGY

Berkelium

ELEMENT

Bk

SYMBOL

97

ATOMIC NUMBER

7440-40-6

CAS NUMBER

ELEMENTAL SPECTRUM

Silver

ELEMENTAL COLOUR

-

REFRACTIVE INDEX

-

POISSON RATIO

16.784 cm³

MOLAR VOLUME

-

BRINELL HARDNESS

-

MOHS HARDNESS

-

VICKERS HARDNESS

-

SPEED OF SOUND

-

BULK MODULUS

-

SHEAR MODULUS

-

YOUNG MODULUS

ALLOTROPES

1,323.15 K, 1,050.00 °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

-

SUPERCONDUCTING POINT

-

MAGNETIC TYPE

-

MASS SUSCEPTIBILITY

-

MOLAR SUSCEPTIBILITY

-

VOLUME SUSCEPTIBILITY

Actinide

CLASSIFICATION

248.072'647'5

ATOMIC WEIGHT

-

ATOMIC RADIUS

168 pm

COVALENT RADIUS SINGLE BOND

139 pm

COVALENT RADIUS DOUBLE BOND

-

COVALENT RADIUS TRIPLE BOND

244 pm

VAN DER WAALS RADIUS

[Rn]7s²5f⁹

ELECTRON CONFIGURATION

Hexagonal, Close Packed Double

CRYSTAL STRUCTURE

14.780'00 g/cm³

DENSITY AS SOLID

-

DENSITY AS LIQUID

-

DENSITY AS GAS

p6₃/mmc

SPACE GROUP NAME

194

SPACE GROUP NUMBER

π/2, π/2 2π/3

LATTICE ANGLES

341.6, 341.6 & 1106.9 pm

LATTICE CONSTANTS

4

VALENCE

1.3

ELECTRONEGATIVITY

-

ELECTRON AFFINITY

IONISATION ENERGY