A wooden artifact from an ancient tomb contains 50 percent of the carbon-14 that is present in living trees.

Question

How long ago, to the nearest year, was the artifact made? (The half-life of carbon-14 is 5730 years.)

Answer 1

0.5a₀ = a₀(0.5)^t/5730

Or logically, half the isotope remains so one half life (5730 years) has passed.