Question

a simple radioactive element with
half life of two minutes initially contains​ 60×10^6atoms. calculate the time it would take for the atom to reduced to 7.5×10^6atoms

Answer 1

Answer:

t=360S

Explanation:

T½=2mins

No=60x10^6

t=?

Nr=7.5x10^6

Nr/No=1/2^n

7.5x10^6/60x10^6=(1/2)^n

0.125=2^- n

Take log to bothsides

Log10^0.125=log10^2^- n

Ln0.125= -nln2

- 2.079= - 0.693n

N=2.079/0.693

N=3

N=t/T

t=nxT

t=3x2x60

t=360s