Decay Simulator: Samarium-167
General data
| Element name | Samarium |
|---|---|
| Chemical symbol | Sm |
| Atomic number Z | 62 |
| Isotope name (symbol) | Samarium-167 (Sm-167) |
| Neutron number N | 105 |
| Mass number A=Z+N | 167 |
Interactive radioactive decay simulation of Samarium-167: atom-by-atom decay, full decay chain, charts of nuclei count and activity.
| Half-life | 330 ms |
|---|
Radioactive decay series
- Samarium-167 330 ms
- Europium-167 860 ms · 84.0%
- Gadolinium-167 4.3 s · 82.4%
- Terbium-167 18.9 s · 82.4%
- Dysprosium-167 6.20 min · 82.4%
- Holmium-167 2.97 h · 82.4%
- Erbium-167 stable · 82.4%
- Europium-166 1.29 s · 16.0%
- Gadolinium-166 5.0 s · 17.5%
- Terbium-166 27.1 s · 17.5%
- Dysprosium-166 81.63 h · 17.5%
- Holmium-166 26.808 h · 17.5%
- Erbium-166 stable · 17.5%
- Gadolinium-165 11.6 s · 0.1%
- Terbium-165 2.11 min · 0.1%
- Dysprosium-165 2.331 h · 0.1%
- Holmium-165 stable · 0.1%
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