The alpha activity of a `10 kg` sample of `._(92)U^(235)` that is used in a nuclear reactor is found to be `x xx 10^(-8)` Bq. If the half of life of uranium -`235` for emitting alpha particles is `7.04xx10^(8)` year, then find the value `'x'`. (Given 1 year `=3.15xx10^(7)s`)

Answer

8

Explanation

No. of radioactive atoms is
`N=m((N_(A))/(M))=2.56xx10^(25)`
`R=lambda N=(ln(2)N)/(T_(1//2))=2.52xx10^(16)` decay/year
`=8xx10^(8)Bq`