Question #190648

How many half-life cycles does it take for a sample of radioactive isotope to reach 12.5% of its original mass?

Expert's answer

If we start with **100% of a sample** , we can keep dividing this number by 2 until we reach 12.5% to find out how many half lives passed.

*Remember, when the sample is still 100%, 0 half lives have passed.*

**% remaining:** 100 > 50 > 25 > 12.5

**Half lives:** -------0------1------2-------3

**3 half lives passed.**

Learn more about our help with Assignments: Chemistry

## Comments

## Leave a comment