Question

Question 4 (2 points)

Manganese-56 decays by beta emission and has a half life of 2.6 hours. If a sample

is analyzed and found to contain 6.25% parent isotopes and 93.75% daughter

isotopes, what must the age of the sample be?

Answer 1

10.4 hours

Step-by-step explanation:

Now from;

0.693/t1/2 = 2.303/t log (No/N)

t1/2= half life of the radioactive isotope

t = age of the radioactive isotope

No= Original amount of radioactive isotope

N= amount of radioactive isotope left after time t

Substituting values;

N = 0.0625No

0.693/2.6 = 2.303/t log (No/0.0625No)

0.693/2.6 = 2.303/t log (1/0.0625)

0.267 = 2.303/t * log 16

0.267 = 2.773/t

t = 2.773/0.267

t = 10.4 hours