Answer:
= 3/4
Step-by-step explanation:
Half life is the time taken by a radioactove element to decay by half of its original mass.
The half life of tritium is 12.3 years , therefore it would take 12.3 years for tritium to decay to a half its original mass.
Using the formula;
New mass = Initial mass × (1/2)^n ; where n is the number of half lives.
n = 5.2 years/12.3 years
= 52/123
Therefore;
New mass = 1 × (1/2)^(52/123)
= 0.74599
= 0.75
The fraction of a tritium sample after 5.20 years will be approximately 3/4