Home
Class 12
CHEMISTRY
80% of the radioactive nuclei present in...

80% of the radioactive nuclei present in a sample is found to remain undecayed after one day. The percentage of undecayed nuclei left after two days will be
a. 64 b. 20 c. 46 d. 80

A

a. 64

B

b. 20

C

c. 46

D

d. 80

Text Solution

Verified by Experts

The correct Answer is:
a. 64
`lambda = (2.303)/(t) log ((N_(0))/(N))`
`= (2.303)/(1) log ((100)/(80)) [t = 1 "day"]`
`lambda = (2.303)/(2) log ((100)/(80)) [t = 2 "days"]`
`(2.303)/(1) log ((100)/(80)) = (2.303)/(2) log ((100)/(N))`
`((5)/(4))^(2) = (100)/(N)`
`N = 64`
Promotional Banner

Topper's Solved these Questions

  • NUCLEAR CHEMISTRY

    CENGAGE CHEMISTRY|Exercise Solved Example|18 Videos

  • NUCLEAR CHEMISTRY

    CENGAGE CHEMISTRY|Exercise Ex6.1 Objective|15 Videos

  • NCERT BASED EXERCISE

    CENGAGE CHEMISTRY|Exercise Nuclear Chemistry (NCERT Exercise)|29 Videos

  • ORGANIC COMPOUNDS WITH FUNCTIONAL GROUP

    CENGAGE CHEMISTRY|Exercise Archives Analytical And Descriptive|24 Videos

Similar Questions

Explore conceptually related problems

90% of the active nuclei present in a radioactive sample are found to remain undecyayed after 1 day. The precentage of undecayed nuclei left after two days will be

80% of the radioactive nuclei are left undecayed in one day then % of nuclei left undecayed after two days will be:

A radioactive sample remains undecayed 9/16 after time t.How much sample remains undecayed after time t/2

A radioactive sample is decayed 20% in one day. After next two days, the undecayed percentage of nuclei will be

90% of a radioactive sample is left undecayed after time t has elapesed. What percentage of the initial sample will decay in a total time 2 t ?

Half life of a radioactive sample is 2x years. What fraction of this sample will remain undecayed after x years?

At a given instant, 60% of the radioactive nuclei in a sample are left undecayed. After 20 s, 85% nuclei have disintegrated , mean life of nuclei

If N_(0) is the number of radioactive nuclei initially present , then the number of nuclei remaining undecayed at the end of nth half life is

The decay constant of a radioactive substance is 1 per month. The percentage of radioactive substance left undecayed after two months will be

If 20% of a radioactive sample decays in 10 days, then the amount of substance left after 20 days will be approximately