Isotope: Mendelevium-246
General data
| Element name | Mendelevium |
|---|---|
| Chemical symbol | Md |
| Atomic number Z | 101 |
| Isotope name (symbol) | Mendelevium-246 (Md-246) |
| Neutron number N | 145 |
| Mass number A=Z+N | 246 |
Ground state
| Half-life | 0.9 ± 0.2 s |
|---|---|
| Mass excess | 76100 ± 300 keV (S) |
Decay branches
α 100% SF EC/β⁺Isomers
| Isomer | Energy | Half-life | Spin / Parity | Decay branches |
|---|---|---|---|---|
| Isomer 1 | - | 4.4 ± 0.8 s | α 23% ECSF 10% EC/β⁺ 77% |
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
- Mendelevium-246 0.9 s
- Einsteinium-242 17.8 s
- Berkelium-238 144 s · 57.4%
- Californium-242 3.49 min · 42.6%
- Curium-238 2.2 h · 83.4%
- Berkelium-242 7.0 min · 16.6%
- Americium-238 97.4 min · 80.3%
- Curium-242 162.88 d · 16.4%
- Plutonium-238 87.7 a · 96.8%
- Plutonium-234 8.8 h · 3.2%
- Neptunium-234 4.4 d · 3.0%
- Uranium-234 2.455×10⁵ a · 99.8%
- Thorium-230 75400 a · 99.8%
- Radium-226 1600 a · 99.8%
- Radon-222 3.82146 d · 99.8%
- Polonium-218 3.097 min · 99.8%
- Lead-214 27.06 min · 99.8%
- Uranium-230 20.23 d · 0.19%
- Thorium-226 30.69 min · 0.19%
- Radium-222 33.6 s · 0.19%
- Astatine-218 1.28 s · 0.022%
- Bismuth-214 19.71 min · 99.8%
- Radon-218 33.75 ms · 0.19%
- Polonium-214 163.48 μs
- Thallium-210 1.30 min · 0.021%
- Lead-210 22.20 a
- Bismuth-210 5.012 d
- Polonium-210 138.378 d
- Lead-206 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 - 9, nuclides - 10.
- Mercury-206 8.32 min · 1.9×10⁻⁶%
- Thallium-206 4.202 min · 1.3×10⁻⁴%
- Lead-209 3.235 h · 1.5×10⁻⁶%
- Bismuth-209 2.01×10¹⁹ a · 1.5×10⁻⁶%
- Thallium-205 stable · 1.5×10⁻⁶%
- Lead-212 10.628 h · 2.6×10⁻⁹%
- Bismuth-212 60.55 min · 2.6×10⁻⁹%
- Polonium-212 295.0 ns · 1.7×10⁻⁹%
- Thallium-208 3.053 min · 9.3×10⁻¹⁰%
- Lead-208 stable · 2.7×10⁻⁹%
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