A radioactive substance is being consumed at a constant of `1 s^(-1)`. After what time will the number of radioactive nuclei becoem `100`. Initially, there were 200 nuceli present.

Options

A. 1 sec
B. 2 sec
C. In (2) sec
D. `(1)/(In (2)) sec`

Answer

b

Explanation

`N = N_(0) e^(-lambda t)`
`100 = 200 e^(-1 xx t)`
`(1)/(2) = e^(-t)`
t = In (2) sec