Question

A radioactive source has a half life of 30 days. During a period of 90 days, the fraction of atoms that would have decayed would be what

Answer 1

so u wanna know the amount of atoms will b decayed. is not it

Answer 2

the formula is\[N=N _{o} e ^{ -\lambda t}\]

Answer 3

here N= number of atoms remaining after 90 days
t= 90 days

Answer 4

\[N _{o}=\] total number of atoms

Answer 5

\[\lambda =\] decay constant

Answer 6

\[\lambda =\frac{ 0.693 }{ T _{\frac{ 1 }{ 2 }} }\]

Answer 7

here \[T _{\frac{ 1 }{ 2 }}=\] half life of radioactive material

Answer 8

now u can try to solve it urself

Answer 9

Thanks Prof Shamin. I have my answer already

Answer 10

A little easier approach for this problem is to realize that with a half-life of 30 days 90 days represent 3 half-lives of decay. you have 1/2 of 1/2 of 1/2 left ie 1/8 of the original amount is left meaning 1-1/8 =7/8 would have decayed

Answer 11

Nice one gleem