I’ve been reading about HL, but I still don’t get why would you use it. So, if half life of coffee is 5h, how that info is relevant when we know that full life is 10 (roughly)? On top of that, how do you get the half-life of a material other than waiting to be completely ‘dead’ and say, ok full life is X, the half life is X/2.
Also, let’s take uranium which in Earth’s crust has a half-life of almost 4.5 billion years.. how did we get this number?
Thank you!
In: Chemistry
Radioactive material can decay at any point in time, it’s random when exactly it decays, but we know about how likely it is to decay. What you have to understand is that the rate of decay depends on the concentration, so the less particles you have left, the less decays you get. So you don’t have a linear curve where there’s zero particles left after 2 half lives. After 2 half lives theres 1/4 the original particles, and then 1/8 and so forth. You never actually get to 0 you only get closer and closer(at least looking at it mathematically, in real life at some point the last particle will decay at some point).
How do we get the number? There’s two ways basically, one is to measure the radioactivity over a long period of time, then you can see how it slows down over time and calculate the half live. The second is to get a precise measurement of how much material you have, and then find the radioactivity, then you can calculate the half live based on that.
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