Polonium-203m1

Properties and data of the isotope ^203m1Po.

Contents

See also: List of individual Polonium isotopes (and general data sources).

General data

Name of the isotope:Polonium-203m1; Po-203m1Symbol:^203m1Po or 203m184PoMass number A:203 (= number of nucleons)Atomic number Z:84 (= number of protons)Neutrons N:119Excitation energy:641.68(17) keVIsotopic mass:202.981416(9) u (atomic weight of Polonium-203m1)Nuclide mass:202.9353407 u (calculated nuclear mass without electrons)Mass excess:-17.31088 MeVMass defect:1.707011692 u (per nucleus)Nuclear binding energy:1590.07114903 MeV (per nucleus)
7.8328628 MeV (average binding energy per nucleon)Half-life:45(2) sDecay constant λ:0.01540327067911 s^-1Specific activity α:4.592112165016 × 10⁺¹⁹ Bq g^-1
1241111395.9504 Ci g^-1Spin and parity:
(nuclear angular momentum)13/2+Magnetic dipole moment:μ(μ_N) = -0.965(67)Quadrupole moment Q:+1.22(20) barn (100 fm²)Nuclear g-factor:g_l = -0.14846153846154

Radioactive Decay

Half-life T_½ = 45(2) s respectively 4.5 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	²⁰³Po	ca. 100 %
EC/β⁺	²⁰³Bi	?

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
²⁰³Po		36.7(5) min	5/2-
^203m2Po	2158.5(6) keV	200 ns

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 119) and isobaric (same nucleon number A = 203) with Polonium-203m1. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 119	Isobar A = 203
73	¹⁹²Ta
74	¹⁹³W
75	¹⁹⁴Re
76	¹⁹⁵Os	²⁰³Os
77	¹⁹⁶Ir	²⁰³Ir
78	¹⁹⁷Pt	²⁰³Pt
79	¹⁹⁸Au	²⁰³Au
80	¹⁹⁹Hg	²⁰³Hg
81	²⁰⁰Tl	²⁰³Tl
82	²⁰¹Pb	²⁰³Pb
83	²⁰²Bi	²⁰³Bi
84	²⁰³Po	²⁰³Po
85	²⁰⁴At	²⁰³At
86	²⁰⁵Rn	²⁰³Rn
87	²⁰⁶Fr	²⁰³Fr
88	²⁰⁷Ra	²⁰³Ra
89	²⁰⁸Ac	²⁰³Ac
90	²⁰⁹Th
91	²¹⁰Pa