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Isotope: Polonium-187

General data

Element namePolonium
Chemical symbolPo
Atomic number Z84
Isotope name (symbol)Polonium-187 (Po-187)
Neutron number N103
Mass number A=Z+N187

Ground state

Half-life1.4 ± 0.3 ms
Spin / Parity(1/2-) (5/2-)
Mass excess2820 ± 30 keV

Decay branches

α ≈ 100%

Isomers

no isomers in the NNDC data

Open Decay Simulator

Produced by decay of

NNDC data contain no decay that leads to this isotope.

Many isotopes are also produced, often mainly, in nuclear reactions (e.g. Co-60 from Co-59 by neutron capture, C-14 from nitrogen-14 in the atmosphere) and in fission (e.g. Cs-137, I-131) - those routes are not listed here.

Radioactive decay series

Rare branches (below 0.01%)

Rare branches are transformations that occur in fewer than 0.01% of decays, e.g. double beta decay or cluster emission. The nuclides they produce are practically absent from a sample, so they are hidden by default to keep the main path clear. In this series: branches - 2, nuclides - 11.

Decay notation

NotationNameOn the chartDescription
αalpha decayAlpha decay is the emission of a helium nucleus (2 protons + 2 neutrons): Z−2, A−4.
β⁻, 2β⁻beta-minus decayIn beta-minus decay a neutron turns into a proton and the nucleus emits an electron: Z+1, A unchanged. 2β⁻ is double beta decay.
EC, EC/β⁺electron capture / beta-plus decayA proton turns into a neutron: the nucleus captures a shell electron (EC) or emits a positron (β⁺): Z−1, A unchanged.
p, 2p, 3pproton emissionProton emission is the ejection of a proton from the nucleus: Z−1, A−1. 2p, 3p - two, three protons.
n, 2n…4nneutron emissionNeutron emission is the ejection of a neutron from the nucleus: A−1, Z unchanged. 2n…4n - several neutrons.
¹⁴C, ²⁴Ne…cluster emissionCluster emission is the ejection of a light nucleus, e.g. ¹⁴C, ²⁰O, ²⁴Ne, ²⁸Mg, ³⁴Si. It is a very rare transformation.
ITisomeric transitionAn isomeric transition takes a nucleus from an excited state (an isomer, e.g. Pa-234m) to the ground state, usually emitting a γ photon: Z and A unchanged.
β⁻n, ECp, ECα…delayed emission Delayed emission is the emission of a particle (n, p or α) right after β⁻ decay or electron capture. The arrow has the colour of the emitted particle and its label shows the transformation, e.g. “β⁻n 63%”.
SFspontaneous fissionno arrowSpontaneous fission is the splitting of a nucleus into two fragments of random masses. There is no single daughter, so the chart shows no arrow - it is listed in the decay branches and in the tile tooltip.

Data sources

More about the data sources