Biology / Unit 1 Bio 0119 short lesson, about 20 seconds
Radioactive Isotopes and Half-Life
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The idea
A radioactive isotope decays at a fixed rate; its half-life is the time for half a starting amount to decay.
In practice
Carbon-14 decays to nitrogen-14 with a half-life near 5,730 years, a rate that neither speeds up nor slows down.
Where people slip
A half-life is a fixed rate, not a countdown to an end date — half of what remains decays in the next half-life.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
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