Two radioactive substances X and Y initially contain equal number of nuclei. X has a half life of 1 hour and Y has a half life of 2 hours. After two hours the ratio of the activity of X to the activity of Y is

Options

A. `1:4`
B. `1:2`
C. `1:1`
D. `2:1`

Answer

C

Explanation

`(N_(1))/(N_(2))=(N_(0)(1/2)^(2/1))/(N_(0)(1/2)^(2/2))=1/2`
`(A_(1))/(A_(2))=(lamda_(1)N_(1))/(lamda_(2)N_(2))=(T_(2)N_(1))/(T_(1)N_(2))[ :. lamda=63/T]`
`(A_(1))/(A_(2))=2/1xx1/2=1/1`