The half-life of carbon-14 is 5600 years. If a sample of wood originally contained 10 grams of carbon-14, how much carbon-14 is left after 1400 years?

Question

I need to do but I have no idea with this. Help me plz ASAP!!!!

Answer 1

All radioactive reactions are first -order reactions. Half life is the amount of time needed to reduce the amount by half. In this case , to 5g. Since t1/2 is 5600 years, after 1400 years we should have more than 5 g.

Let us calculate: t1/2 = 0.693/k , k = 0.000124 year-1

ln(At/Ao) = -kt ; Ao is 10g, t = 1400 years, we calculated k

Substitute and find At which is what you need to find.