How is tossing a coin similar to radioactive decay of an element?

Answer 1

If you toss a coin, there are fifty percent chances of getting the head or tail. In the radioactive decay also fifty percent atoms will brake down. When you toss the coin next time, you have 25 percent chances of getting the head or tail repeated. Same is the case with radioactive material. you will be left with 25 percent of the radioactive material after half life. Third time the chances of getting the same head or tail is 12.5 percent. Here you are left with 12.5 percent of the radioactive material left with after another half life.

Answer 2

The similarity lies in the randomness - in the case of radioactive decay, you can't predict when an individual atom will decay. Each individual atom has a 50% chance of decaying within one half-life, but you can't predict which atoms will decay and which won't. However, with a large number of atoms, say one kilogram of them, you can predict that half a kilogram will decay within one half-life, and you would be pretty close.