Periodic Table/Fermium/²⁵¹Fm

← 250Fm252Fm →

²⁵¹Fm

Fermium-251

Radioactive· Half-life: 5.30 h

Nuclear Propertiesbinding energy · spin-parity · abundance

Protons (Z)

100

Neutrons (N)

151

Mass Number (A)

251

Atomic Mass

251.081545AMU

Spin / Parity

9/2-

Binding E/A

7.253keV

Natural Abundance

Trace / None

Half-life

5.30 h

Decay Modesoverview · half-life · α · β⁻ · β⁺

β⁺

98.2%

α

1.8%

Decay Chain

²⁵¹FmFermium5.30 h

β⁺98.2%

α²⁴⁷Cf1.80%

²⁵¹EsEinsteinium1.38 d

EC99.5%

α²⁴⁷Bk0.50%

²⁵¹CfCalifornium898 y

α100.0%

²⁴⁷CmCurium15.6 My

α100.0%

²⁴³PuPlutonium4.96 h

β⁻100.0%

²⁴³AmAmericium7.35 ky

α100.0%

²³⁹NpNeptunium2.36 d

β⁻100.0%

α²³⁵Pa

²³⁹PuPlutonium24.1 ky

α100.0%

²³⁵UUranium704 My

α100.0%

20Ne²¹⁵Pb8.00%

25Ne²¹⁰Pb8.00%

28Mg²⁰⁷Hg8.00%

²³¹ThThorium1.06 d

β⁻100.0%

²³¹PaProtactinium32.6 ky

α100.0%

24Ne²⁰⁷Tl13.4%

23F²⁰⁸Pb9.90%

²²⁷AcActinium21.8 y

β⁻98.6%

α²²³Fr1.38%

²²⁷ThThorium18.7 d

α100.0%

²²³RaRadium11.4 d

α100.0%

¹⁴C²⁰⁹Pb8.90%

²¹⁹RnRadon3.96 s

α100.0%

²¹⁵PoPolonium1.78 ms

α100.0%

β⁻²¹⁵At2.30%

²¹¹PbLead36.2 min

β⁻100.0%

²¹¹BiBismuth2.14 min

α100.0%

β⁻²¹¹Po0.28%

²⁰⁷TlThallium4.77 min

β⁻100.0%

²⁰⁷PbLeadSTABLE

20-step decay chain → stable · Primary path shown · branching ratios indicated

Other Isotopes of Fermium

241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260

← Back to FermiumData: IAEA NDS · ENSDF