To calibrate the x-axis for 14c decay, you have to convert half-lives to number of years. recall that 14c has a single half-life of 5,730 years. how many years make up 5 half-lives for 14c?
The biological half-life or terminal half-life of a substance is the time it takes for a substance to lose half of its amount. Having 5 half lives would be five times the half life. Therefore, 5 half lives of 14-C is equal to 28650 years. Hope this answers the question. Have a nice day.