In an agriculture experiment, a solution containing 1 mole of a radioactive meterial `(t_(1//2)=14.3 days)`was injected into the roots of a plants.the plant was allowed 70 hours to settle down and then activity eas measured in its fruit. If the activity measured was `1 mu Ci` what per cent of activity is transmitted from the root to the fruit in steady state?

Answer

A, B

Explanation

`R_0=lambdaN=(0.693)/(14.3xx3600xx24)xx6.02xx10^23` per sec
`=3.37xx10^17` per sec
After 70 hours activity,
`R=R_0e^(-lambdat)=(3.37xx10^17)e^(-(0.693//14.3xx24)(70))`
`=2.92xx10^17` per sec
In fruits activity was observed `1muCi` or
`3.7xx10^4` per sec. Therefore, percentage of activity transmitted from root to the fruit.
`=(3.7xx10^4)/(2.92xx10^17)xx100`
`1.26xx10^-11%`