Answer:
The time an unstable nuclei takes to decay is called the half-life of a radioactive isotope.
The half-life of a radioisotope is important in radioactive dating because it can be used to calculate the age of fossils by measuring the carbon absorbed.
Explanation:
1450 W
<u>5800n x 20m</u> =1450w
80s
1.7 mol/dm3
working out in the image