Answer:
1/8
Explanation:
Use logic,
every one hour, half of a radioactive remains
for the first hour, half remains
for the second hour, half of half remains or quarter remains
for the third hour, 1/2 of 1/2 of 1/2 or 1/8 remains
or use this equation
[tex]n = r ({ \frac{1}{2} })^{ \frac{f}{t} } [/tex]
where
n = amount after f time
r = amount of the original isotope
f = time
t = half-life
