Question

In 240 years ,a radioactive material remain 1/16th of its initial value find half life and decay constant of radioactive material​

Answer 1

activity of radioactive substance at any time t is given by

⇒N=N

0

e

−λt

given that

N

0

N

=

16

1

at time t=40days

⇒

16

1

=e

−40λ

⇒e

40λ

=16

⇒λ=

40

ln16

we know that

t

2

1

=

λ

ln2

after putting the value of λ in above equation

⇒t

2

1

=

ln16

ln2

×40=10

This is the right answer for your question.