Question

Fluorine-21 has a half-life of approximately 20 seconds. What fraction of the original element would remain after 1 minute?

Answer 1

The correct answer would be = 1/32.

Step-by-step explanation:

The half-life is the time required for a quantity to reduce to half of the initial value of an object or element.

it is given that Fluorine-21 has a half-life time = 12 seconds

then in a minute the number of half-lives,

12 seconds = 12/60 of a minute or 1/5 of a minute

This means in 1 minute we will half the sample 5 times.

(1/2)^5 = 1/32 is the fractional remainder