Nuclear decay is an example of a purely statistical process. A more precise definition of half-life is that each nucleus has a 50% chance of living for a time equal to one half-life t 1 / 2 t 1 / 2 size 12{t rSub { size 8{1/2} } } {}. Thus, if N N size 12{N} {} is reasonably large, half of the original nuclei decay in a time of one half-life
Sodium-24 has a half-life of 15 hours. How much sodium-24 will remain in an 18.0 g sample after 60 hours? 60/15=4 half-lives, 2^-4 X18=1.125 grams of Sodium-24 left after 60 hours.
If you graph half life data you get an exponential decay curve. It’s kind of the definition of it. If you graph something that starts at 100 and decays by half every 1 minute, 50 by minute 2, 25 by 3, 12.5 by 4, 6.25 by 5 etc. you’ll see. . 220 64 0 82 339 43 170 103 70