Question

Griffin was walking to school one day and found a old bone. He took it to a scientist friend of his, and after studying the bone, she determined it was approximately 24,000 years old. She also told him that the current amount of carbon-14 in the bone was 5,000 atoms. How many atoms must the bone have had originaly, assuming that the half-life of carbon-14 is approximately 6,000 years.

Answer 1

This problem is easily solvable because radioactivity equations are common and well-established. The pseudo-first reaction is written below:

A = A₀(1/2)^(t/h)
where
A is the final amount
A₀ is the original amount
t is the time
h is the half life

5,000 = A₀(1/2)^(24,000/6,000)
Solving for A₀,
A₀ = 80,000 atoms