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A radioactive substance decay to 1/5 of ...

A radioactive substance decay to `1/5` of its original value in 56 days. The decay constant is

A

`9.2xx10^(-2)` per day

B

`2.2xx10^(-2)` per day

C

`2.8xx10^(-2)` per day

D

`9.9xx10^(-2)` per day

Text Solution

Verified by Experts

The correct Answer is:
C
`lambda=2.303/t "log" N_(0)/N`
`=2.303/56"log" 5/1=(2.303xx0.6990)/56`
`=2.8xx10^(-2)` per year
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