Decay Simulator: Curium-235
General data
| Element name | Curium |
|---|---|
| Chemical symbol | Cm |
| Atomic number Z | 96 |
| Isotope name (symbol) | Curium-235 (Cm-235) |
| Neutron number N | 139 |
| Mass number A=Z+N | 235 |
Interactive radioactive decay simulation of Curium-235: atom-by-atom decay, full decay chain, charts of nuclei count and activity.
| Half-life | 300 s |
|---|
Radioactive decay series
- Curium-235 300 s
- Americium-235 10.3 min · 99.0%
- Plutonium-235 25.3 min · 98.6%
- Neptunium-235 396.1 d · 98.6%
- Uranium-235 7.040×10⁸ a · 98.6%
- Thorium-231 25.52 h · 98.6%
- Plutonium-231 8.6 min · 1.0%
- Neptunium-231 48.8 min · 1.3%
- Uranium-231 4.2 d · 1.3%
- Protactinium-231 32740 a · 99.9%
- Actinium-227 21.773 a · 99.9%
- Francium-223 21.99 min · 1.4%
- Uranium-227 1.1 min · 0.1%
- Thorium-223 0.60 s · 0.1%
- Radium-219 9 ms · 0.1%
- Radon-215 2.3 μs · 0.1%
- Protactinium-227 38.3 min · 0.026%
- Thorium-227 18.694 d · 98.5%
- Actinium-223 2.12 min · 0.022%
- Radium-223 11.4352 d · 99.9%
- Francium-219 22 ms · 0.022%
- Radon-219 3.96 s · 99.9%
- Polonium-215 1.781 ms · 99.9%
- Lead-211 36.1648 min · 99.9%
- Astatine-215 37 μs · 0.022%
- Bismuth-211 2.14 min · 99.9%
- Polonium-211 0.516 s · 0.38%
- Thallium-207 4.77 min · 99.6%
- Lead-207 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 - 5, nuclides - 13.
- Astatine-219 56 s · 8.3×10⁻⁵%
- Lead-209 3.235 h · 8.9×10⁻⁸%
- Bismuth-209 2.01×10¹⁹ a · 8.9×10⁻⁸%
- Thallium-205 stable · 8.9×10⁻⁸%
- Lead-215 142 s · 7.9×10⁻¹⁰%
- Bismuth-215 7.6 min · 7.7×10⁻⁵%
- Lead-210 22.20 a · 7.9×10⁻¹⁰%
- Mercury-207 2.9 min · 7.9×10⁻¹⁰%
- Bismuth-210 5.012 d · 7.9×10⁻¹⁰%
- Polonium-210 138.378 d · 7.9×10⁻¹⁰%
- Mercury-206 8.32 min · 1.5×10⁻¹⁷%
- Thallium-206 4.202 min · 1.1×10⁻¹⁵%
- Lead-206 stable · 7.9×10⁻¹⁰%
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