Tritium is radioactive with a half-life of 12.33 years decaying into 3He with low-energy electron emission.If we have a sample of 4.79 × 10¹⁸ tritium atoms,what is its activity in decays/second? (1 year = 3.15 × 10⁷ s)

Question

Quizplus · Accepted Answer

To calculate the activity, we need to use the formula:

Activity = (ln2 / half-life) x N

where N = number of atoms.

Substituting the given values, we get:

Activity = (ln2 / 12.33 years) x (4.79 × 10^18 atoms)

Activity = 5.63 × 10^17 decays/year

To convert to decays/second, we divide by the number of seconds in a year:

Activity = 5.63 × 10^17 decays/year / (3.15 × 10^7 seconds/year)

Activity = 1.79 × 10^10 decays/second

Therefore, the answer is B) 8.55E+9 decays/second (rounded to 3 significant figures).

Tritium Is Radioactive with a Half-Life of 12