Isotope: Arsenic-91
General data
| Element name | Arsenic |
|---|---|
| Chemical symbol | As |
| Atomic number Z | 33 |
| Isotope name (symbol) | Arsenic-91 (As-91) |
| Neutron number N | 58 |
| Mass number A=Z+N | 91 |
Ground state
| Half-life | unknown |
|---|---|
| Mass excess | -36500 ± 400 keV (S) |
Decay branches
β⁻ 100% β⁻n β⁻2nIsomers
no isomers in the NNDC data
No half-life data - simulation unavailable.
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
- Arsenic-91 unknown
- Selenium-91 270 ms
- Bromine-91 544 ms · 79.0%
- Krypton-91 8.57 s · 55.5%
- Rubidium-91 58.0 s · 55.5%
- Strontium-91 9.68 h · 55.5%
- Yttrium-91 58.56 d · 55.5%
- Zirconium-91 stable · 55.5%
- Bromine-90 1.91 s · 21.0%
- Krypton-90 32.32 s · 39.2%
- Rubidium-90 158 s · 39.2%
- Strontium-90 28.905 a · 39.2%
- Yttrium-90 64.05 h · 39.2%
- Zirconium-90 stable · 39.2%
- Krypton-89 3.15 min · 5.3%
- Rubidium-89 15.39 min · 5.3%
- Strontium-89 50.56 d · 5.3%
- Yttrium-89 stable · 5.3%
Decay notation
| Notation | Name | On the chart | Description |
|---|---|---|---|
| α | alpha decay | Alpha decay is the emission of a helium nucleus (2 protons + 2 neutrons): Z−2, A−4. | |
| β⁻, 2β⁻ | beta-minus decay | In 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 decay | A proton turns into a neutron: the nucleus captures a shell electron (EC) or emits a positron (β⁺): Z−1, A unchanged. | |
| p, 2p, 3p | proton emission | Proton emission is the ejection of a proton from the nucleus: Z−1, A−1. 2p, 3p - two, three protons. | |
| n, 2n…4n | neutron emission | Neutron emission is the ejection of a neutron from the nucleus: A−1, Z unchanged. 2n…4n - several neutrons. | |
| ¹⁴C, ²⁴Ne… | cluster emission | Cluster emission is the ejection of a light nucleus, e.g. ¹⁴C, ²⁰O, ²⁴Ne, ²⁸Mg, ³⁴Si. It is a very rare transformation. | |
| IT | isomeric transition | An 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%”. | |
| SF | spontaneous fission | no arrow | Spontaneous 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
- NNDC Wallet Cards 2023 - Data as of 15 October 2024 - licence: Public domain