Fermium (Fm)

chemical element with the atomic number of 100

Atomic Number	100
Atomic Weight	257
Massagetal	241

Group
Period	7
Block	f

proton	100 p⁺
neutron	141 n⁰
elektron	100 e^-

Physical Property

Atoomradius
molar volume
Covalent Radius	167 pm
Metallic Radius
Ioonradius	110,5 pm
Crystal Radius	124,5 pm
Van der Waals radius	245 pm 328,6 pm
density	9,7 g/cm³

Chemical Property

energie

proton affinity
electron affinity
ionization energy	6,5 eV/particle 10 eV/particle 23,2 eV/particle 39,3 eV/particle 55 eV/particle 74 eV/particle 93 eV/particle 120 eV/particle 136 eV/particle 162 eV/particle 185 eV/particle 209 eV/particle 237 eV/particle 257 eV/particle 276 eV/particle 300 eV/particle 326 eV/particle 351 eV/particle 377 eV/particle 402 eV/particle 430 eV/particle 453 eV/particle 616 eV/particle 647 eV/particle 680 eV/particle 716 eV/particle 749 eV/particle 782 eV/particle 837 eV/particle 871 eV/particle 909 eV/particle 944 eV/particle 1 110 eV/particle 1 150 eV/particle 1 190 eV/particle 1 230 eV/particle 1 370 eV/particle 1 420 eV/particle 1 550 eV/particle 1 600 eV/particle 1 770 eV/particle 1 860 eV/particle 1 940 eV/particle 2 030 eV/particle 2 120 eV/particle 2 210 eV/particle 2 300 eV/particle 2 390 eV/particle 2 490 eV/particle 2 590 eV/particle 2 680 eV/particle 2 760 eV/particle 2 900 eV/particle 2 950 eV/particle 3 403 eV/particle 3 480 eV/particle 3 561 eV/particle 3 647 eV/particle 3 730 eV/particle 3 810 eV/particle 3 986 eV/particle 4 070 eV/particle 4 160 eV/particle 4 245 eV/particle 4 586 eV/particle 4 670 eV/particle 4 760 eV/particle 4 840 eV/particle 5 420 eV/particle 5 510 eV/particle 5 760 eV/particle 5 860 eV/particle 9 200 eV/particle 9 370 eV/particle 9 570 eV/particle 9 770 eV/particle 9 970 eV/particle 10 160 eV/particle 10 660 eV/particle 10 860 eV/particle 11 080 eV/particle 11 280 eV/particle 11 850 eV/particle 12 020 eV/particle 12 220 eV/particle 12 390 eV/particle 14 180 eV/particle 14 400 eV/particle 14 800 eV/particle 15 000 eV/particle 30 300 eV/particle 30 800 eV/particle 31 300 eV/particle 31 800 eV/particle 38 400 eV/particle 39 100 eV/particle 40 000 eV/particle 40 482,2 eV/particle 158 152,5 eV/particle 160 804 eV/particle

Verdampingswarmte
smeltingswarmte
Vormingsentalpie
elektron

Elektronskil	2, 8, 18, 32, 30, 8, 2

Valenselektrone	2 ⓘ

elektronkonfigurasie	[Rn] 5f¹² 7s²ⓘ 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 5f¹² 7s²

Oksidasietoestand	2, 3
Elektronegatiwiteit	0.22485
Electrophilicity Index
fundamental state of matter

phase of matter	Solid
gaseous state of matter
Boiling Point
Melting Point	1 800,15 K
critical pressure
critical temperature
triple point
appearance
kleur	Colorless #ffffff #b31fba #b31fba
appearance
Brekingsindeks
thermodynamic material property
Thermal Conductivity
thermal expansion
molar heat capacity
Specific Heat Capacity
heat capacity ratio
electrical properties
type
Geleidingsvermoë
Elektriese resistiwiteit
superconductivity
Magnetisme
type
magnetic susceptibility (Mass)
magnetic susceptibility (Molar)
magnetic susceptibility (Volume)
magnetic ordering
Curie temperature
Néel temperature
structure
Crystal Structure	()
lattice constant
Lattice Angles
mechanical property
hardness
Massamodulus
Skuifmodulus
Young se modulus
Poisson se verhouding
Spoed van klank
classification
Category	Actinides, Actinides
CAS Group
IUPAC Group
Glawe Number	44
Mendeleev Number	36
Pettifor Number	37
Geochemical Class
Goldschmidt classification	synthetic

other

Gas Basicity
polarizability	113 ± 20 a₀
C6 Dispersion Coefficient
allotrope
Neutron cross section	5 800
Neutron Mass Absorption
quantum number	3H6
Ruimtegroep	()

Isotopes of Fermium

Stable Isotopes	0
Unstable Isotopes	20
Natural Isotopes	0

²⁴¹Fm

Massagetal	241
neutron number	141
Relative Atomic Mass	241,074311 ± 0,000322 Da
g-factor
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	730 ± 60 us
spin	5/2
nuclear quadrupole moment
ontdekkingsdatum	2008
parity	+

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

²⁴²Fm

Massagetal	242
neutron number	142
Relative Atomic Mass	242,07343 ± 0,00043 Da
g-factor	0
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	800 ± 200 us
spin	0
nuclear quadrupole moment	0
ontdekkingsdatum	1975
parity	+

decay mode	intensity
SF (spontaneous fission)	100%
α (α emission)

²⁴³Fm

Massagetal	243
neutron number	143
Relative Atomic Mass	243,074414 ± 0,00014 Da
g-factor
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	231 ± 9 ms
spin	7/2
nuclear quadrupole moment
ontdekkingsdatum	1981
parity	-

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

²⁴⁴Fm

Massagetal	244
neutron number	144
Relative Atomic Mass	244,074036 ± 0,000216 Da
g-factor	0
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	3,12 ± 0,08 ms
spin	0
nuclear quadrupole moment	0
ontdekkingsdatum	1967
parity	+

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

²⁴⁵Fm

Massagetal	245
neutron number	145
Relative Atomic Mass	245,075354 ± 0,00021 Da
g-factor
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	4,2 ± 1,3 s
spin	1/2
nuclear quadrupole moment	0
ontdekkingsdatum	1967
parity	+

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

²⁴⁶Fm

Massagetal	246
neutron number	146
Relative Atomic Mass	246,075353334 ± 0,000014675 Da
g-factor	0
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	1,54 ± 0,04 s
spin	0
nuclear quadrupole moment	0
ontdekkingsdatum	1966
parity	+

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

²⁴⁷Fm

Massagetal	247
neutron number	147
Relative Atomic Mass	247,076944 ± 0,000194 Da
g-factor
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	31 ± 1 s
spin	7/2
nuclear quadrupole moment
ontdekkingsdatum	1967
parity	+

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

²⁴⁸Fm

Massagetal	248
neutron number	148
Relative Atomic Mass	248,077185451 ± 0,000009122 Da
g-factor	0
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	34,5 ± 1,2 s
spin	0
nuclear quadrupole moment	0
ontdekkingsdatum	1958
parity	+

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

²⁴⁹Fm

Massagetal	249
neutron number	149
Relative Atomic Mass	249,078926042 ± 0,000006668 Da
g-factor
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	1,6 ± 0,1 m
spin	7/2
nuclear quadrupole moment
ontdekkingsdatum	1960
parity	+

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

²⁵⁰Fm

Massagetal	250
neutron number	150
Relative Atomic Mass	250,079519765 ± 0,000008468 Da
g-factor	0
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	31 ± 1,1 m
spin	0
nuclear quadrupole moment	0
ontdekkingsdatum	1954
parity	+

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

²⁵¹Fm

Massagetal	251
neutron number	151
Relative Atomic Mass	251,08154513 ± 0,000015342 Da
g-factor
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	5,3 ± 0,08 h
spin	9/2
nuclear quadrupole moment
ontdekkingsdatum	1957
parity	-

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

²⁵²Fm

Massagetal	252
neutron number	152
Relative Atomic Mass	252,082466019 ± 0,000005604 Da
g-factor	0
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	25,39 ± 0,04 h
spin	0
nuclear quadrupole moment	0
ontdekkingsdatum	1956
parity	+

decay mode	intensity
α (α emission)	100%
SF (spontaneous fission)	0.0023%
2β⁺ (double β⁺ decay)

²⁵³Fm

Massagetal	253
neutron number	153
Relative Atomic Mass	253,085180945 ± 0,000001662 Da
g-factor
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	3 ± 0,12 d
spin	1/2
nuclear quadrupole moment	0
ontdekkingsdatum	1957
parity	+

decay mode	intensity
ϵ (electron capture)	88%
α (α emission)	12%

²⁵⁴Fm

Massagetal	254
neutron number	154
Relative Atomic Mass	254,086852424 ± 0,000001978 Da
g-factor	0
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	3,24 ± 0,002 h
spin	0
nuclear quadrupole moment	0
ontdekkingsdatum	1954
parity	+

decay mode	intensity
α (α emission)	99.9408%
SF (spontaneous fission)	0.0592%

²⁵⁵Fm

Massagetal	255
neutron number	155
Relative Atomic Mass	255,089963495 ± 0,000004223 Da
g-factor
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	20,07 ± 0,07 h
spin	7/2
nuclear quadrupole moment
ontdekkingsdatum	1954
parity	+

decay mode	intensity
α (α emission)	100%
SF (spontaneous fission)	2.4%

²⁵⁶Fm

Massagetal	256
neutron number	156
Relative Atomic Mass	256,091771699 ± 0,000003241 Da
g-factor	0
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	157,1 ± 1,3 m
spin	0
nuclear quadrupole moment	0
ontdekkingsdatum	1955
parity	+

decay mode	intensity
SF (spontaneous fission)	91.9%
α (α emission)	8.1%

²⁵⁷Fm

Massagetal	257
neutron number	157
Relative Atomic Mass	257,095105419 ± 0,000004669 Da
g-factor
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	100,5 ± 0,2 d
spin	9/2
nuclear quadrupole moment
ontdekkingsdatum	1964
parity	+

decay mode	intensity
α (α emission)	99.79%
SF (spontaneous fission)	0.21%

²⁵⁸Fm

Massagetal	258
neutron number	158
Relative Atomic Mass	258,097077 ± 0,000215 Da
g-factor	0
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	370 ± 14 us
spin	0
nuclear quadrupole moment	0
ontdekkingsdatum	1971
parity	+

decay mode	intensity
SF (spontaneous fission)	100%
α (α emission)

²⁵⁹Fm

Massagetal	259
neutron number	159
Relative Atomic Mass	259,100596 ± 0,000304 Da
g-factor
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd	1,5 ± 0,2 s
spin
nuclear quadrupole moment
ontdekkingsdatum	1980
parity

decay mode	intensity
SF (spontaneous fission)	100%

²⁶⁰Fm

Massagetal	260
neutron number	160
Relative Atomic Mass	260,102809 ± 0,000467 Da
g-factor	0
natural abundance
radioaktiwiteit	☢️ radioactive element
Halfleeftyd
spin	0
nuclear quadrupole moment	0
ontdekkingsdatum
parity	+

decay mode	intensity
SF (spontaneous fission)

geskiedenis

Ontdek deur	Argonne, Los Alamos, U of Calif
ligging van ontdekking	United States
ontdekkingsdatum	1953
etimologie	Named in honor of the scientist Enrico Fermi.
uitspraak	FER-mi-em (Engels)

source

Abundance
Abundance in Earth's crust
natural abundance (oseaan)
natural abundance (human body)	0 %
natural abundance (Meteoroïde)	0 %
natural abundance (Son)	0 %
Abundance in Universe	0 %

Nuclear Screening Constants

Fermium on ChemicalAid

Australian Educational Vocabulary ID	scot/3519
CAS Registry Number	7440-72-4
ChEBI ID	33394
ChemSpider ID	22434
DSSTOX compound identifier	DTXCID60147884
DSSTox substance ID	DTXSID60225393
Den Store Danske ID	fermium
Encyclopædia Britannica Online ID	science/fermium
Encyclopædia Universalis ID	fermium
Freebase-kode	/m/025rqck
GND ID	4490995-0
Gran Enciclopèdia Catalana ID	0108657
Great Russian Encyclopedia Online ID	4709674
InChI	InChI=1S/Fm
InChIKey	MIORUQGGZCBUGO-UHFFFAOYSA-N
KBpedia ID	Fermium
MeSH descriptor ID	D005286
OmegaWiki Defined Meaning	158627
PubChem CID	23998
Römpp online ID	RD-06-00507
Store norske leksikon ID	fermium
Treccani ID	fermio
UNII	Q70I3KBF4W
USGS Thesaurus ID	1453
WordNet 3.1 Synset ID	14661517-n

Fermium (Fm)

Physical Property

Chemical Property

other

Isotopes of Fermium

241Fm

242Fm

243Fm

244Fm

245Fm

246Fm

247Fm

248Fm

249Fm

250Fm

251Fm

252Fm

253Fm

254Fm

255Fm

256Fm

257Fm

258Fm

259Fm

260Fm

geskiedenis

source

Nuclear Screening Constants

²⁴¹Fm

²⁴²Fm

²⁴³Fm

²⁴⁴Fm

²⁴⁵Fm

²⁴⁶Fm

²⁴⁷Fm

²⁴⁸Fm

²⁴⁹Fm

²⁵⁰Fm

²⁵¹Fm

²⁵²Fm

²⁵³Fm

²⁵⁴Fm

²⁵⁵Fm

²⁵⁶Fm

²⁵⁷Fm

²⁵⁸Fm

²⁵⁹Fm

²⁶⁰Fm