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Technical data for Fermium

Click any property name to see plots of that property for all the elements.

Overview
NameFermium
SymbolFm
Atomic Number100
Atomic Weight257[note]
DensityN/A
Melting Point1527 °C
Boiling PointN/A

Thermal properties
PhaseN/A
Melting Point1527 °C
Boiling PointN/A
Absolute Melting Point1.8×103 K
Absolute Boiling PointN/A
Critical PressureN/A
Critical TemperatureN/A
Heat of FusionN/A
Heat of VaporizationN/A
Heat of CombustionN/A
Specific HeatN/A
Adiabatic IndexN/A
Neel PointN/A
Thermal ConductivityN/A
Thermal ExpansionN/A

Bulk physical properties
DensityN/A
Density (Liquid)N/A
Molar VolumeN/A
Brinell HardnessN/A
Mohs HardnessN/A
Vickers HardnessN/A
Bulk ModulusN/A
Shear ModulusN/A
Young ModulusN/A
Poisson RatioN/A
Refractive IndexN/A
Speed of SoundN/A
Thermal ConductivityN/A
Thermal ExpansionN/A

Reactivity
Valence3
Electronegativity1.3
ElectronAffinityN/A
Ionization Energies
627 kJ/mol

Health and Safety
Autoignition PointN/A
FlashpointN/A
Heat of CombustionN/A
DOT Hazard ClassN/A
DOT NumbersN/A
EU NumberN/A
NFPA Fire RatingN/A
NFPA HazardsN/A
NFPA Health RatingN/A
NFPA Reactivity RatingN/A
RTECS NumberN/A
NFPA LabelN/A

Classifications
Alternate NamesNone
Names of AllotropesNone
Blockf
GroupN/A
Period7
Electron Configuration[Rn]5f127s2
ColorN/A
Discovery
1952 in United States
Gas phaseN/A
CAS NumberCAS7440-72-4
CID NumberN/A
Gmelin NumberN/A
NSC NumberN/A
RTECS NumberN/A

Electrical properties
Electrical TypeN/A
Electrical ConductivityN/A
ResistivityN/A
Superconducting PointN/A

Magnetic properties
Magnetic TypeN/A
Curie PointN/A
Mass Magnetic SusceptibilityN/A
Molar Magnetic SusceptibilityN/A
Volume Magnetic SusceptibilityN/A

Abundances
% in UniverseN/A
% in SunNone
% in MeteoritesNone
% in Earth's CrustNone
% in OceansNone
% in HumansNone

Atomic dimensions and structure
Atomic RadiusN/A
Covalent RadiusN/A
Van der Waals RadiusN/A
Crystal StructureN/A
Lattice AnglesN/A
Lattice ConstantsN/A
Space Group NameN/A
Space Group NumberN/A

Nuclear Properties
Half-Life100.5 d
Lifetime145.02 d
Decay ModeAlphaEmission
Quantum Numbers3H6
Neutron Cross Section5.8×103
Neutron Mass AbsorptionN/A
Known Isotopes
242Fm, 243Fm, 244Fm, 245Fm, 246Fm, 247Fm, 248Fm, 249Fm, 250Fm, 251Fm, 252Fm, 253Fm, 254Fm, 255Fm, 256Fm, 257Fm, 258Fm, 259Fm, 260Fm
Stable Isotopes
Isotopic Abundances


Notes on the properties of Fermium:

Atomic Weight: Atomic mass number given for longest lived isotope.

Up to date, curated data provided by
Mathematica's ElementData function from Wolfram Research, Inc.

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