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Two nuclei P, Q have equal number of ato...

Two nuclei P, Q have equal number of atoms at t = 0. Their half-lives are 3 hours and 9 hours respectively. Compare their rates of disintegration, after 18 hours from the start.

Text Solution

Verified by Experts

Number of half-lives of P in 18h = `18/3` = 6
Number of nuclei of P left undecayed after 6 half-lives,
`N_(1)=N(1/2)^(6)`
Number of half-lives of Q in 18h = `18/9` = 2
Number of nuclei of Q left undecayed after 2 half-lives
`N_(2)=N(1/2)^(2)`
`R_(1)/R_(2)=(lamda_(1)N_(1))/(lamda_(2)N_(2))=(T_(2)N_(1))/(T_(1)N_(2))" "[thereforeT=0.693/lamda]`
= `9/3xx(N(1/2)^(6))/(N(1/2)^(2))=3/16=3.16`
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