Chemistry

Radioactive decay follows an exponential pattern where the sample shrinks by the same fraction in each half-life period. The key is to count how many halvings occurred: if you start with 2.0 mg and end at 0.25 mg, you can figure out the ratio between them, then work backward to find how long one half-life takes. Think of it like repeatedly cutting a cake in half—how many cuts does it take to go from your starting amount to what's left?

Radioactive decay follows an exponential pattern where the sample shrinks by the same fraction in each half-life period. The key is to count how many halvings occurred: if you start with 2.0 mg and end at 0.25 mg, you can figure out the ratio between them, then work backward to find how long one half-life takes. Think of it like repeatedly cutting a cake in half—how many cuts does it take to go from your starting amount to what's left?