A radio - active sample of half- life 10 days contains 1000 x nuclei . Number of original nuclie present after 5 days is

Options

A. 707x
B. 750x
C. 500x
D. 250x

Answer

a

Explanation

Half life of sample `tau_(1//2)= (In2)/(lamda)Rightarrowlamda= (In2)/(10)` distintegration per day .
`N(t)= N_(0)e^(-(lamdat))`
`=N_(0)^(e)=(1n2)/(10xx5)=N_(0)^(e)-(In2)/(2)`
`N(t)=N_(0)e^(-Insqrt2)=N_(0)e^(In1//sqrt2)`
`N(t)= (N_(0))/(sqrt2)= (1000x)/(sqrt2)=707x`