Question

The half-life of a radioactive substance is 5 years. In how much time, 10g of this substance will reduce to 2.5g?

Answer 1

Answer:

HII mate,

as radioactive substances are example of first order reaction, so

T1/2= 0.693/k

( T1/2 = 5 years)

k = 0.693/5

T = 2.303/k log R1/R2

  = 2.303*5/ 0.693 log 10/2.5

  = 2.303*5 / 0.693 log4

  = 2.303 * 5 * 0.6/ 0.693              (  log 4 = 0.6)

   = 9.96 = 10 years (approx.)