The activity of a radioactive substance is `R_(1)` at time `t_(1)` and `R_(2)` at time `t_(2)(gt t_(1))`. Its decay cosntant is `lambda`. Then .

Options

A. `R_(1)t_(1) = R_(2)t_(2)`
B. `R_(2) = R_(1) e^(lambda(t_(2) - t_(1)))`
C. `R_(2) = R_(1) e^(lambda(t_(1) - t_(2))`
D. `(R_(1) - R_(2))/(t_(2) - t_(1))`= constant

Answer

c

Explanation

`(R_(2))/(R_(1)) = (R_(0) e^(-lambda t_(2)))/(R_(0) e^(-lambda t_(1))), R_(2) = R_(1) e^(lambda(t_(1) - t_(2)))`