Radioactive dating graphs
In fact, if you were to graph your results by putting the time on the x-axis and the number of 'radioactive' coins on the y-axis, you should almost always end up with a graph that looks like this.In nuclear reactions, most likely instead of starting out with 16 atoms or even 100 atoms, you would be measuring the amount you have in grams (or some other mass unit).All you need is a bunch of pennies (or any other type of coin) and a clock or stopwatch. When the 30 seconds have passed, dump your coins on a table and remove all the 'heads'. The 'heads' represent 'decayed' atoms, and they will no longer be part of our sample.We are going to assign a half-life of 30 seconds to this made-up radioactive element. Write down how many remain, and shake the remaining coins for another 30 seconds.Again, after 30 seconds have passed, dump your coins on a table and remove all the 'heads.' Write down how many remain, and continue this process until all your coins have 'decayed.' Notice at the end how you can never have half of a coin, so when you're down to just one or two coins, you can see the probabilistic nature of them decaying.You may end up shaking one coin for many 30-second half-lives because it just won't decay!The same rules still apply: If I start out with 20 grams of carbon-14 and wait about 5,730 years (the half-life of carbon-14), around 10 grams will remain and 10 grams will have been converted into nitrogen-14 (that's the product of a carbon-14 atom that underwent beta decay).This is how carbon dating works, and it's used to determine how old an artifact is.
Now, we can never have half of an atom, so what happens next?
This is where probability makes more of a presence. If it doesn't, then it has a 50% chance of decaying in the next 5.27 years.
If I wait 5.27 more years, there is a 50% chance that the one remaining cobalt-60 atom will decay. One thing that is really neat about half-life is that it can be simulated very easily. As you're waiting, shake up the coins in a container or in your hands so they get all mixed up.
The half-life of a radioactive isotope is the time it takes for half of the sample to react, or decay.
This time can range anywhere from a portion of a second to thousands of years depending on the identity of the starting isotope.Try it risk-free What causes a radioactive particle to decay?