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

Options

A. nearly `63%` of the radioactive substnce will decay in `(1//0.173)` year.
B. half-life of the radioactive substance is `(1//0.173)` year
C. One-fourth of the radioactive substance will be left after 8 years
D. All of the above

Answer

a,c

Explanation

`lambda =(0.173 year)^(-1)`
`N=N_(0) e^(- lambda t)`
As `t=(1)/(lambda)`,hence
`N= (N_(0))/(e) =(N_(0))/(2.178)=0.37 N_(0)`
`rArr T=(0.693)/(lambda)=(0.693)/(0.173)=4 years`.