The radioactivity due to `C-14` isotope (half-life = 6000 years) of a sample of wood form an ancient tomb was found to be nearly half that of fresh wood. The bomb is there for about how many years old? a)3000 b)6000 c)9000 d)12000

Options

A. 5700 yr
B. 2850 yr
C. 11400 yr
D. 22800 yr

Answer

C

Explanation

`(N_(0))/(N)=1/4=((1)/(2))^(t//5700)`
`therefore" "((1)/(2))^(2)=((1)/(2))^(t//5700)`
`therefore" "(t)/(5700)=2`
`therefore` The age of the wood, t = 11400 yr