Isotope: Americium-244
General data
| Element name | Americium |
|---|---|
| Chemical symbol | Am |
| Atomic number Z | 95 |
| Isotope name (symbol) | Americium-244 (Am-244) |
| Neutron number N | 149 |
| Mass number A=Z+N | 244 |
Ground state
| Half-life | 10.02 ± 0.03 h |
|---|---|
| Spin / Parity | (6-) |
| Mass excess | 59879.1 ± 1.5 keV |
Decay branches
β⁻ 100%Isomers
| Isomer | Energy | Half-life | Spin / Parity | Decay branches |
|---|---|---|---|---|
| Isomer 1 | 89.5 ± 1.6 keV | 26.1 ± 0.4 min | 1+ | β⁻ 99.9636 ± 0.0012% EC 0.0364 ± 0.0012% |
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
- Americium-244 10.02 h
- Curium-244 18.11 a
- Plutonium-240 6562 a
- Uranium-236 2.343×10⁷ a
- Thorium-232 1.407×10¹⁰ a
- Radium-228 5.75 a
- Actinium-228 6.15 h
- Thorium-228 1.9116 a
- Radium-224 3.6313 d
- Radon-220 55.6 s
- Polonium-216 144.0 ms
- Lead-212 10.628 h
- Bismuth-212 60.55 min
- Polonium-212 295.0 ns · 64.1%
- Thallium-208 3.053 min · 35.9%
- Lead-208 stable
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 - 1, nuclides - 6.
- Lead-210 22.20 a · 4.0×10⁻⁹%
- Bismuth-210 5.012 d · 4.0×10⁻⁹%
- Polonium-210 138.378 d · 4.0×10⁻⁹%
- Mercury-206 8.32 min · 7.6×10⁻¹⁷%
- Thallium-206 4.202 min · 5.4×10⁻¹⁵%
- Lead-206 stable · 4.0×10⁻⁹%
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