Recently, the skeleton of King Richard III was found under a parking lot in England. If tissue samples from the skeleton contain about 93.79% of the carbon-14 expected in living tissue, what year did King Richard III die? The half-life for carbon-14 is 5730 years.

218.29 years

Explanation:

Initial Concentration = 100%

Final Concentration = 93.79%

Half life = 5730 years

Time = ?

Decays are first ordeer reactions, we have;

t1/2 = 0.693 / k

k = 0.693 / t1/2

k =  0.00012094 y-1

From the integrated rate law of first order reactions;

ln[A] = ln[A]o - kt

kt = ln[A]o - ln[A]

kt = ln(0.9739) - ln(1)

kt = 0.0264

t = 0.0264 / 0.00012094

t = 218.29 years