The decay constant of a radioactive substance is` 0.173 year^(-1)`. Therefore,

Options

A. Nearly `63%` of the radioactive substance will decay in `(1//0.173)` year.
B. half-life of the radio active subtance is `(1//0.173)` year.
C. one-forth of the radioactive substance will be left after nerarly `8` years.
D. half of the substance will decay in one average life time.

Answer

A, C

Explanation

Given , `lambda=0.173`
`T_(1//2)=(ln2)/(lambda)=(0.693)/(0.173)~=4`
Also `N_(0)-N=N_(0)e^(-lambdat)`
For `t=(1)/(0.173)"year"`
`N_(0)-N=(N_(0))/(e )=0.37N_(0)`