Decay Simulator: Fermium-241
General data
| Element name | Fermium |
|---|---|
| Chemical symbol | Fm |
| Atomic number Z | 100 |
| Isotope name (symbol) | Fermium-241 (Fm-241) |
| Neutron number N | 141 |
| Mass number A=Z+N | 241 |
Interactive radioactive decay simulation of Fermium-241: atom-by-atom decay, full decay chain, charts of nuclei count and activity.
| Half-life | 0.73 ms |
|---|
Radioactive decay series
- Fermium-241 0.73 ms
- Californium-237 0.8 s · 53.8%
- Curium-233 23 s · 53.8%
- Einsteinium-241 4.3 s · 46.2%
- Americium-233 3.2 min · 43.1%
- Plutonium-233 20.9 min · 41.1%
- Neptunium-233 36.2 min · 41.1%
- Uranium-233 1.5919×10⁵ a · 41.1%
- Plutonium-229 80 s · 10.8%
- Neptunium-229 4.0 min · 7.3%
- Uranium-225 61 ms · 5.4%
- Thorium-221 1.73 ms · 5.4%
- Radium-217 1.59 μs · 5.4%
- Radon-213 19.38 ms · 5.4%
- Polonium-209 124 a · 5.4%
- Lead-205 1.70×10⁷ a · 5.4%
- Protactinium-225 1.7 s · 5.0%
- Actinium-221 52 ms · 5.0%
- Francium-217 22 μs · 5.0%
- Astatine-213 124 ns · 5.0%
- Uranium-229 57.8 min · 2.4%
- Protactinium-229 1.55 d · 1.9%
- Thorium-229 7908 a · 43.0%
- Radium-225 14.8 d · 43.0%
- Thorium-225 8.72 min · 0.48%
- Actinium-225 9.9190 d · 43.1%
- Francium-221 4.801 min · 43.1%
- Astatine-217 32.6 ms · 43.0%
- Bismuth-213 45.61 min · 43.0%
- Thallium-209 2.162 min · 0.92%
- Radium-221 16 s · 0.43%
- Radon-217 0.59 ms · 0.44%
- Polonium-213 3.706 μs · 42.6%
- Lead-209 3.235 h · 43.5%
- Bismuth-209 2.01×10¹⁹ a · 48.5%
- Thallium-205 stable · 53.8%
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 - 3, nuclides - 4.
- Bismuth-211 2.14 min · 2.3×10⁻¹⁰%
- Thallium-207 4.77 min · 2.7×10⁻¹⁰%
- Polonium-211 0.516 s · 6.3×10⁻¹³%
- Lead-207 stable · 2.7×10⁻¹⁰%
How to read the simulation
Grid: each pixel is one atom of the starting isotope. When an atom decays, the pixel takes the colour of the decay product - in decay series mode the product can decay further. The moment each atom decays is random, but the probability follows from the half-life, so after one T½ about half of the atoms remain, after two - about a quarter.
Chart N(t): what percentage of the sample atoms each nuclide makes up at a given moment. The line of the starting isotope falls (by half after each T½), the lines of stable products rise, and those of short-lived ones first rise, then fall.
Chart A(t): activity, i.e. the number of decays per second (becquerel, Bq). It depends on the number of atoms and on how fast they decay: for the same number of atoms, the shorter the T½, the higher the activity.
Simulation time runs faster (or slower) than real time - the time scale slider sets the multiplier. This way you can watch the decay of isotopes that live from fractions of a second to billions of years.
Well-known isotopes
- H-3 - Tritium - glowing watch hands, nuclear fusion fuel.
- C-14 - Radiocarbon dating.
- K-40 - Natural radioactivity - in bananas and in our bodies.
- Co-60 - Radiotherapy and radiation sterilization.
- I-131 - Thyroid treatment; Chernobyl fallout.
- Cs-137 - Long-lasting contamination after Chernobyl and Fukushima.
- Rn-222 - Radon in basements and mines.
- Ra-226 - The longest-lived isotope of radium - the element discovered by Marie and Pierre Curie in 1898.
- U-235 - Nuclear power plant fuel; start of the actinium series.
- U-238 - Age of the Earth; start of the uranium series.
- Pu-238 - Power source for space probes (Voyager, Curiosity rover).
- Am-241 - Ionization smoke detectors.
Data sources
- NNDC Wallet Cards 2023 - Data as of 15 October 2024 - licence: Public domain