Decay Simulator: Actinium-215
General data
| Element name | Actinium |
|---|---|
| Chemical symbol | Ac |
| Atomic number Z | 89 |
| Isotope name (symbol) | Actinium-215 (Ac-215) |
| Neutron number N | 126 |
| Mass number A=Z+N | 215 |
Interactive radioactive decay simulation of Actinium-215: atom-by-atom decay, full decay chain, charts of nuclei count and activity.
| Half-life | 170 ms |
|---|
Radioactive decay series
- Actinium-215 170 ms
- Francium-211 3.10 min · 99.9%
- Astatine-207 1.81 h · 86.9%
- Bismuth-203 11.76 h · 8.7%
- Radium-215 1.68 ms · 0.09%
- Radon-211 14.7 h · 13.1%
- Polonium-207 5.80 h · 81.8%
- Astatine-211 7.216 h · 9.5%
- Bismuth-207 31.22 a · 85.8%
- Lead-203 51.93 h · 8.7%
- Thallium-203 stable · 8.7%
- Polonium-211 0.516 s · 5.5%
- Lead-207 stable · 91.3%
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