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If N(0) is the original mass of the subs...

If `N_(0)` is the original mass of the substance of half - life period `t_(1//2) = 5 year` then the amount of substance left after `15` year is

A

`(N_(0))/8`

B

`(N_(0))/16`

C

`(N_(0))/2`

D

`(N_(0))/4`

Text Solution

Verified by Experts

The correct Answer is:
A
`N_(0)` is the initial amount of substance and N is the amount left after decay. Then number nuclei left after successive disintegration is given by
`N=N_(0)(1/2)^(n)`
n= no. oif half lives `=1/(t_(1//2))=15/5=3`
Therefore `N=N_(0)(1/2)^(3)=(N_(0))/8`
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