Nobelium-250

Properties and data of the isotope ²⁵⁰No.

Contents

General data

Name of the isotope:Nobelium-250; No-250Symbol:²⁵⁰No or 250102NoMass number A:250 (= number of nucleons)Atomic number Z:102 (= number of protons)Neutrons N:148Isotopic mass:250.08756(21) u (atomic weight of Nobelium-250)Nuclide mass:250.0316133 u (calculated nuclear mass without electrons)Mass excess:81.56161 MeVMass defect:1.993000832 u (per nucleus)Nuclear binding energy:1856.468317 MeV (per nucleus)
7.42587327 MeV (average binding energy per nucleon)Separation energy:S_N = 8.29(34) MeV (first neutron)
S_P = 2.96(28) MeV (first proton)Half-life:4.2 μsDecay constant λ:165035.04299046 s^-1Specific activity α:3.975457102857 × 10⁺²⁶ Bq g^-1
1.074447865637 × 10⁺¹⁶ Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:2003

Radioactive Decay

Half-life T_½ = 4.2 μs respectively 4.2 × 10^-6 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
SF < 100 %	div.	> 98 %
α	²⁴⁶Fm	< 2 %	8.95(20) MeV

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
^250mNo	1050 keV	46 μs	(6+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 148) and isobaric (same nucleon number A = 250) with Nobelium-250. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 148	Isobar A = 250
90	²³⁸Th
91	²³⁹Pa
92	²⁴⁰U
93	²⁴¹Np
94	²⁴²Pu
95	²⁴³Am
96	²⁴⁴Cm	²⁵⁰Cm
97	²⁴⁵Bk	²⁵⁰Bk
98	²⁴⁶Cf	²⁵⁰Cf
99	²⁴⁷Es	²⁵⁰Es
100	²⁴⁸Fm	²⁵⁰Fm
101	²⁴⁹Md	²⁵⁰Md
102	²⁵⁰No	²⁵⁰No
103	²⁵¹Lr