Decay Simulator: Radon-195

General data

Radioactive decay series

• Radon-195 6 ms
• Polonium-191 22 ms
• Lead-187 15.2 s
• Thallium-187 ≈ 51 s · 90.5%
• Mercury-187 1.9 min · 90.5%
• Gold-187 8.3 min · 90.5%
• Platinum-187 2.35 h · 90.5%
• Iridium-187 10.5 h · 90.5%
• Osmium-187 stable · 90.5%
• Mercury-183 8.9 s · 9.5%
• Gold-183 42.8 s · 7.3%
• Platinum-183 6.5 min · 7.2%
• Iridium-183 58 min · 7.2%
• Osmium-183 13.0 h · 7.2%
• Rhenium-183 70.0 d · 7.2%
• Tungsten-183 stable · 7.2%
• Platinum-179 21.2 s · 2.2%
• Iridium-179 79 s · 2.3%
• Osmium-179 6.3 min · 2.3%
• Rhenium-179 19.5 min · 2.3%
• Tungsten-179 37.05 min · 2.3%
• Tantalum-179 1.82 a · 2.3%
• Hafnium-179 stable · 2.3%

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 - 2, nuclides - 16.

• Osmium-175 1.4 min · 0.0054%
• Rhenium-175 5.89 min · 0.0054%
• Tungsten-175 35.2 min · 0.0054%
• Tantalum-175 10.5 h · 0.0054%
• Hafnium-175 70.67 d · 0.0054%
• Lutetium-175 stable · 0.0054%
• Platinum-182 2.7 min · 2.5×10⁻⁵%
• Iridium-182 15 min · 2.5×10⁻⁵%
• Osmium-182 22.04 h · 2.5×10⁻⁵%
• Rhenium-182 64.2 h · 2.5×10⁻⁵%
• Tungsten-182 stable · 2.5×10⁻⁵%
• Osmium-178 5.0 min · 9.4×10⁻⁹%
• Rhenium-178 13.2 min · 9.4×10⁻⁹%
• Tungsten-178 21.6 d · 9.4×10⁻⁹%
• Tantalum-178 2.41 h · 9.4×10⁻⁹%
• Hafnium-178 stable · 9.4×10⁻⁹%

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.