Mathematically, this is written as A= λN where A is the amount of radioactivity (decays per second) and N is the number of radioactive atoms.
The way to find out how many atoms will decay in a given amount of time is to count (or calculate) the number of radioactive atoms and to multiply this by the fraction of those atoms that will decay in a second. One curie of radioactive material will undergo 37 billion decays every second one Becquerel of radioactivity will undergo 1 decay every second. Radioactivity measures the number of radioactive decays an amount of radioactivity will undergo in a second. The next part of this is to turn this into a measure of radioactivity. What this tells us is that any particular Co-60 atom has a 13.15% chance of decaying during the course of a year, or that 13.15% of the atoms in a bunch of Co-60 will decay during a year. So for Co-60 (which has a half-life of 5.27 years) the decay constant is equal to 0.693/5.27 years = 0.1315 yr -1, which you would read as 0.1315 per year. The natural logarithm of 2 (ln 2) is roughly equal to 0.693 and t 1/2 is the half-life of the nuclide you’re calculating activity for. Or, if you have a bunch of radioactive atoms, the decay constant tells us how many of those (what percentage of them) will decay away in a given amount of time. The decay constant is simply the probability that given atom will have a radioactive decay in a particular amount of time. The first concept is something called a decay constant, which is represented mathematically with the Greek letter lambda (λ). Luckily it’s not too involved, so let’s walk through it a step at a time. That’s the good news – but it will take going through a bit of math to see how these all fit in with one another. You’re right – these factors are all tied together, and the relationship is fairly straightforward. For example, I know there’s some sort of relationship between a nuclide’s half-life, its mass, and the amount of activity per gram but I’m not quite sure how these all go together.
Zoomie – I am trying to brush up on some of my radiation knowledge and am having some trouble figuring out some of the calculations and concepts about radioactivity. Except explicit open source licence (indicated Creative Commons / free), the "Radioactivity Calculator" algorithm, the applet or snippet (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, translator), or the "Radioactivity Calculator" functions (calculate, convert, solve, decrypt / encrypt, decipher / cipher, decode / encode, translate) written in any informatic language (Python, Java, PHP, C#, Javascript, Matlab, etc.Dear Dr. Ask a new question Source codeĭCode retains ownership of the "Radioactivity Calculator" source code.
Tritium has been present in large numbers on Earth since nuclear tests. Radiometric dating is the technique using a radioactive isotope present in a material (generally Carbon in carbon 14 dating) to determine the age of a material (several hundred or thousand years old) via the calculations above.įor shorter durations (decades), and recent materials, tritium dating is used.