Fermi

Fermi (Fm)

chemical element with the atomic number of 100
Atomic Number100
Atomic Weight257
Rhif màs241
Group
Period7
Blockf
Proton100 p+
Niwtron141 n0
Electron100 e-
Animated Bohr model of Fm (Fermi)

Nodwedd Ffisegol

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

Nodwedd Gemegol

egni
proton affinity
electron affinity
ionization energy
ionization energy of Fm (Fermi)
enthalpy of vaporization
enthalpy of fusion
standard enthalpy of formation
Electron
plisgyn yr electron2, 8, 18, 32, 30, 8, 2
Bohr model: Fm (Fermi)
valence electron2
Lewis structure: Fm (Fermi)
trefn yr electronnau[Rn] 5f12 7s2
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 5f12 7s2
Enhanced Bohr model of Fm (Fermi)
Orbital Diagram of Fm (Fermi)
Cyflwr ocsidiad2, 3
Electronegatifedd
Electrophilicity Index
cyflwr sylfaenol mater
cyflwr materSolid
gaseous state of matter
Boiling Point
Melting Point
1,800.15 K
critical pressure
critical temperature
triple point
appearance
lliw
Colorless
appearance
Mynegrif plygiant
nodwedd ffisegol gwrthrych
Thermal Conductivity
thermal expansion
molar heat capacity
Specific Heat Capacity
heat capacity ratio
electrical properties
type
dargludedd trydanol
Gwrthedd
superconductivity
magnetism
type
magnetic susceptibility (Mass)
magnetic susceptibility (Molar)
magnetic susceptibility (Volume)
magnetic ordering
Curie temperature
Néel temperature
strwythur
Crystal Structure ()
lattice constant
Lattice Angles
nodwedd mecanyddol deunyddiau
hardness
bulk modulus
shear modulus
Young's modulus
Poisson's ratio
speed of sound
classification
CategoryActinides, Actinides
CAS Group
IUPAC Group
Glawe Number44
Mendeleev Number36
Pettifor Number37
Geochemical Class
Goldschmidt classificationsynthetic

other

Gas Basicity
polarizability
113 ± 20 a₀
C6 Dispersion Coefficient
allotrope
Neutron cross section
5,800
Neutron Mass Absorption
quantum number3H6
space group ()

Isotopes of Fermium

Stable Isotopes0
Unstable Isotopes20
Natural Isotopes0

241Fm

Rhif màs241
neutron number141
relative atomic mass
241.074311 ± 0.000322 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
730 ± 60 us
spin5/2
nuclear quadrupole moment
dyddiad darganfod2008
parity+

decay modeintensity
SF (spontaneous fission)
α (α emission)14%
β+ (β+ decay; β+ = ϵ + e+)12%

242Fm

Rhif màs242
neutron number142
relative atomic mass
242.07343 ± 0.00043 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
800 ± 200 us
spin0
nuclear quadrupole moment
0
dyddiad darganfod1975
parity+

decay modeintensity
SF (spontaneous fission)100%
α (α emission)

243Fm

Rhif màs243
neutron number143
relative atomic mass
243.074414 ± 0.00014 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
231 ± 9 ms
spin7/2
nuclear quadrupole moment
dyddiad darganfod1981
parity-

decay modeintensity
α (α emission)91%
SF (spontaneous fission)9%
β+ (β+ decay; β+ = ϵ + e+)

244Fm

Rhif màs244
neutron number144
relative atomic mass
244.074036 ± 0.000216 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
3.12 ± 0.08 ms
spin0
nuclear quadrupole moment
0
dyddiad darganfod1967
parity+

decay modeintensity
SF (spontaneous fission)97%
β+ (β+ decay; β+ = ϵ + e+)2%
α (α emission)1%

245Fm

Rhif màs245
neutron number145
relative atomic mass
245.075354 ± 0.00021 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
4.2 ± 1.3 s
spin1/2
nuclear quadrupole moment
0
dyddiad darganfod1967
parity+

decay modeintensity
α (α emission)100%
β+ (β+ decay; β+ = ϵ + e+)7%
SF (spontaneous fission)0.3%

246Fm

Rhif màs246
neutron number146
relative atomic mass
246.075353334 ± 0.000014675 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
1.54 ± 0.04 s
spin0
nuclear quadrupole moment
0
dyddiad darganfod1966
parity+

decay modeintensity
α (α emission)93.2%
SF (spontaneous fission)6.8%
ϵ (electron capture)1.3%

247Fm

Rhif màs247
neutron number147
relative atomic mass
247.076944 ± 0.000194 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
31 ± 1 s
spin7/2
nuclear quadrupole moment
dyddiad darganfod1967
parity+

decay modeintensity
α (α emission)64%
β+ (β+ decay; β+ = ϵ + e+)

248Fm

Rhif màs248
neutron number148
relative atomic mass
248.077185451 ± 0.000009122 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
34.5 ± 1.2 s
spin0
nuclear quadrupole moment
0
dyddiad darganfod1958
parity+

decay modeintensity
α (α emission)100%
β+ (β+ decay; β+ = ϵ + e+)
SF (spontaneous fission)0.1%

249Fm

Rhif màs249
neutron number149
relative atomic mass
249.078926042 ± 0.000006668 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
1.6 ± 0.1 m
spin7/2
nuclear quadrupole moment
dyddiad darganfod1960
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)
α (α emission)33%

250Fm

Rhif màs250
neutron number150
relative atomic mass
250.079519765 ± 0.000008468 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
31 ± 1.1 m
spin0
nuclear quadrupole moment
0
dyddiad darganfod1954
parity+

decay modeintensity
α (α emission)100%
SF (spontaneous fission)0.0069%
ϵ (electron capture)

251Fm

Rhif màs251
neutron number151
relative atomic mass
251.08154513 ± 0.000015342 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
5.3 ± 0.08 h
spin9/2
nuclear quadrupole moment
dyddiad darganfod1957
parity-

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)98.2%
α (α emission)1.8%

252Fm

Rhif màs252
neutron number152
relative atomic mass
252.082466019 ± 0.000005604 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
25.39 ± 0.04 h
spin0
nuclear quadrupole moment
0
dyddiad darganfod1956
parity+

decay modeintensity
α (α emission)100%
SF (spontaneous fission)0.0023%
+ (double β+ decay)

253Fm

Rhif màs253
neutron number153
relative atomic mass
253.085180945 ± 0.000001662 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
3 ± 0.12 d
spin1/2
nuclear quadrupole moment
0
dyddiad darganfod1957
parity+

decay modeintensity
ϵ (electron capture)88%
α (α emission)12%

254Fm

Rhif màs254
neutron number154
relative atomic mass
254.086852424 ± 0.000001978 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
3.24 ± 0.002 h
spin0
nuclear quadrupole moment
0
dyddiad darganfod1954
parity+

decay modeintensity
α (α emission)99.9408%
SF (spontaneous fission)0.0592%

255Fm

Rhif màs255
neutron number155
relative atomic mass
255.089963495 ± 0.000004223 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
20.07 ± 0.07 h
spin7/2
nuclear quadrupole moment
dyddiad darganfod1954
parity+

decay modeintensity
α (α emission)100%
SF (spontaneous fission)2.4%

256Fm

Rhif màs256
neutron number156
relative atomic mass
256.091771699 ± 0.000003241 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
157.1 ± 1.3 m
spin0
nuclear quadrupole moment
0
dyddiad darganfod1955
parity+

decay modeintensity
SF (spontaneous fission)91.9%
α (α emission)8.1%

257Fm

Rhif màs257
neutron number157
relative atomic mass
257.095105419 ± 0.000004669 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
100.5 ± 0.2 d
spin9/2
nuclear quadrupole moment
dyddiad darganfod1964
parity+

decay modeintensity
α (α emission)99.79%
SF (spontaneous fission)0.21%

258Fm

Rhif màs258
neutron number158
relative atomic mass
258.097077 ± 0.000215 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
370 ± 14 us
spin0
nuclear quadrupole moment
0
dyddiad darganfod1971
parity+

decay modeintensity
SF (spontaneous fission)100%
α (α emission)

259Fm

Rhif màs259
neutron number159
relative atomic mass
259.100596 ± 0.000304 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
1.5 ± 0.2 s
spin
nuclear quadrupole moment
dyddiad darganfod1980
parity

decay modeintensity
SF (spontaneous fission)100%

260Fm

Rhif màs260
neutron number160
relative atomic mass
260.102809 ± 0.000467 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
spin0
nuclear quadrupole moment
0
dyddiad darganfod
parity+

decay modeintensity
SF (spontaneous fission)
Fermium-Ytterbium Alloy
Electron shell 100 Fermium

hanes

darganfyddwr neu ddyfeisiwrArgonne, Los Alamos, U of Calif
man darganfodUnited States
dyddiad darganfod1953
geirdarddiadNamed in honor of the scientist Enrico Fermi.
ynganiadFER-mi-em (Saesneg)

source

Abundance
Abundance in Earth's crust
natural abundance (cefnfor)
natural abundance (corff dynol)
0 %
natural abundance (Awyrfaen)
0 %
natural abundance (Haul)
0 %
Abundance in Universe
0 %

Nuclear Screening Constants