Atomic Number | 100 |
---|---|
Atomic Weight | 257 |
Mass Number | 241 |
Group | |
---|---|
Period | 7 |
Block | f |
Protons | 100 p+ |
---|---|
Neutrons | 141 n0 |
Electrons | 100 e- |
Atomic Radius | |
---|---|
Molar Volume | |
Covalent Radius | 167 pm
|
Metallic Radius | |
Ionic Radius | 110.5 pm
|
Crystal Radius | 124.5 pm
|
Van der Waals Radius |
245 pm
|
Density | 9.7 g/cm³
|
Energy | |
Proton Affinity | |
Electron Affinity | |
Ionization Energy | 6.5 eV/particle
|
Heat of Vaporization | |
Heat of Fusion | |
Heat of Formation | |
Electrons | |
Electron Shells | 2, 8, 18, 32, 30, 8, 2 |
Valence Electrons | 2 |
Electron Configuration | [Rn] 5f12 7s2 |
Oxidation States | 2, 3 |
Electronegativity | |
Electrophilicity | |
Phases | |
Phase | Solid |
Gas Phase | |
Boiling Point | |
Melting Point | 1,800.15 K
|
Critical Pressure | |
Critical Temperature | |
Triple Point | |
Visual | |
Color | Colorless
|
Appearance | |
Refractive Index | |
Thermodynamic Properties | |
Thermal Conductivity | |
Thermal Expansion | |
Molar Heat Capacity | |
Specific Heat Capacity | |
Heat Capacity Ratio (Adiabatic Index) | |
Electrical Properties | |
Type | |
Electrical Conductivity | |
Electrical Resistivity | |
Superconducting Point | |
Magnetism | |
Type | |
Magnetic Susceptibility (Mass) | |
Magnetic Susceptibility (Molar) | |
Magnetic Susceptibility (Volume) | |
Magnetic Ordering | |
Curie Point | |
Neel Point | |
Structure | |
Crystal Structure | () |
Lattice Constant | |
Lattice Angles | |
Mechanical Properties | |
Hardness | |
Bulk Modulus | |
Shear Modulus | |
Young Modulus | |
Poisson Ratio | |
Speed of Sound | |
Classification | |
Category | Actinides, Actinides |
CAS Group | |
IUPAC Group | |
Glawe Number | 44 |
Mendeleev Number | 36 |
Pettifor Number | 37 |
Geochemical Class | |
Goldschmidt Class | synthetic |
Other | |
Gas Basicity | |
Dipole Polarizability | |
C6 Dispersion Coefficient | |
Allotropes | |
Neutron Cross Section | 5,800
|
Neutron Mass Absorption | |
Quantum Numbers | 3H6 |
Space Group | () |
Stable Isotopes | 0 |
---|---|
Unstable Isotopes | 20 |
Radioactive Isotopes | 20 |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 241 |
G-Factor | |
Half Life | 730 ± 60 us
|
Spin | 5/2 |
Quadrupole Moment | |
Discovery Year | 2008 |
Parity | + |
Decay Mode | Intensity |
---|---|
SF (spontaneous fission) | % |
α (α emission) | 14% |
β+ (β+ decay; β+ = ϵ + e+) | 12% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 242 |
G-Factor | 0
|
Half Life | 800 ± 200 us
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1975 |
Parity | + |
Decay Mode | Intensity |
---|---|
SF (spontaneous fission) | 100% |
α (α emission) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 243 |
G-Factor | |
Half Life | 231 ± 9 ms
|
Spin | 7/2 |
Quadrupole Moment | |
Discovery Year | 1981 |
Parity | - |
Decay Mode | Intensity |
---|---|
α (α emission) | 91% |
SF (spontaneous fission) | 9% |
β+ (β+ decay; β+ = ϵ + e+) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 244 |
G-Factor | 0
|
Half Life | 3.12 ± 0.08 ms
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1967 |
Parity | + |
Decay Mode | Intensity |
---|---|
SF (spontaneous fission) | 97% |
β+ (β+ decay; β+ = ϵ + e+) | 2% |
α (α emission) | 1% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 245 |
G-Factor | |
Half Life | 4.2 ± 1.3 s
|
Spin | 1/2 |
Quadrupole Moment | 0
|
Discovery Year | 1967 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
β+ (β+ decay; β+ = ϵ + e+) | 7% |
SF (spontaneous fission) | 0.3% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 246 |
G-Factor | 0
|
Half Life | 1.54 ± 0.04 s
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1966 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 93.2% |
SF (spontaneous fission) | 6.8% |
ϵ (electron capture) | 1.3% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 247 |
G-Factor | |
Half Life | 31 ± 1 s
|
Spin | 7/2 |
Quadrupole Moment | |
Discovery Year | 1967 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 64% |
β+ (β+ decay; β+ = ϵ + e+) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 248 |
G-Factor | 0
|
Half Life | 34.5 ± 1.2 s
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1958 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
β+ (β+ decay; β+ = ϵ + e+) | % |
SF (spontaneous fission) | 0.1% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 249 |
G-Factor | |
Half Life | 1.6 ± 0.1 m
|
Spin | 7/2 |
Quadrupole Moment | |
Discovery Year | 1960 |
Parity | + |
Decay Mode | Intensity |
---|---|
β+ (β+ decay; β+ = ϵ + e+) | % |
α (α emission) | 33% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 250 |
G-Factor | 0
|
Half Life | 31 ± 1.1 m
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1954 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
SF (spontaneous fission) | 0.0069% |
ϵ (electron capture) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 251 |
G-Factor | |
Half Life | 5.3 ± 0.08 h
|
Spin | 9/2 |
Quadrupole Moment | |
Discovery Year | 1957 |
Parity | - |
Decay Mode | Intensity |
---|---|
β+ (β+ decay; β+ = ϵ + e+) | 98.2% |
α (α emission) | 1.8% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 252 |
G-Factor | 0
|
Half Life | 25.39 ± 0.04 h
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1956 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
SF (spontaneous fission) | 0.0023% |
2β+ (double β+ decay) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 253 |
G-Factor | |
Half Life | 3 ± 0.12 d
|
Spin | 1/2 |
Quadrupole Moment | 0
|
Discovery Year | 1957 |
Parity | + |
Decay Mode | Intensity |
---|---|
ϵ (electron capture) | 88% |
α (α emission) | 12% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 254 |
G-Factor | 0
|
Half Life | 3.24 ± 0.002 h
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1954 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 99.9408% |
SF (spontaneous fission) | 0.0592% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 255 |
G-Factor | |
Half Life | 20.07 ± 0.07 h
|
Spin | 7/2 |
Quadrupole Moment | |
Discovery Year | 1954 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
SF (spontaneous fission) | 2.4% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 256 |
G-Factor | 0
|
Half Life | 157.1 ± 1.3 m
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1955 |
Parity | + |
Decay Mode | Intensity |
---|---|
SF (spontaneous fission) | 91.9% |
α (α emission) | 8.1% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 257 |
G-Factor | |
Half Life | 100.5 ± 0.2 d
|
Spin | 9/2 |
Quadrupole Moment | |
Discovery Year | 1964 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 99.79% |
SF (spontaneous fission) | 0.21% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 258 |
G-Factor | 0
|
Half Life | 370 ± 14 us
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1971 |
Parity | + |
Decay Mode | Intensity |
---|---|
SF (spontaneous fission) | 100% |
α (α emission) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 259 |
G-Factor | |
Half Life | 1.5 ± 0.2 s
|
Spin | |
Quadrupole Moment | |
Discovery Year | 1980 |
Parity |
Decay Mode | Intensity |
---|---|
SF (spontaneous fission) | 100% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 260 |
G-Factor | 0
|
Half Life | |
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | |
Parity | + |
Decay Mode | Intensity |
---|---|
SF (spontaneous fission) | % |
Fermium was discovered as a component of the debris of the first hydrogen bomb explosion in 1952. It was identified by Albert Ghiorso and co-workers at the University of California, Berkeley in collaboration with the Argonne and Los Alamos National Laboratories, in the fallout from the Ivy Mike nuclear test. The new element was produced by the nuclear fission of 17 neutrons with uranium-238. Named after Nobel laureate Enrico Fermi, one of the pioneers of nuclear physics
Discoverers | Argonne, Los Alamos, U of Calif |
---|---|
Discovery Location | United States |
Discovery Year | 1953 |
Etymology (Name Origin) | Named in honor of the scientist Enrico Fermi. |
Pronunciation | FER-mi-em (English) |
Produced by bombarding lighter transuranium elements with still lighter particles or by neutron capture.
Abundance | |
---|---|
Abundance in Earth's crust | |
Abundance in Oceans | |
Abundance in Human Body | 0 %
|
Abundance in Meteor | 0 %
|
Abundance in Sun | 0 %
|
Abundance in Universe | 0 %
|