Home
Class 12
CHEMISTRY
The mean lives of a radioactive substanc...

The mean lives of a radioactive substance are 1620 years and 405 years of `alpha`-emission and `beta`-emission respectively. Find out the time during which three-fourth of a sample will decay if it is decaying both by `alpha`-emission and `beta`-emission simultaneously.

Text Solution

Verified by Experts

For succiessive `alpha, beta`-emission
`K_("avg") = K_(alpha) + K_(beta) = (1)/(1620) + (1)/(405) = (5)/(1620) "years"^(-1)`
Given at `t = t`, `N = 1//4 N_(0)` (since `3//4` part decays)
`t = (2.303)/(K_("avg")) "log" (N_(0))/(N)`
`= (2.303 xx 1620)/(5) "log" 4 = 449.24` years
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • NUCLEAR CHEMISTRY

    CENGAGE CHEMISTRY|Exercise Ex6.1 Objective|15 Videos

  • NUCLEAR CHEMISTRY

    CENGAGE CHEMISTRY|Exercise Ex6.2 Objective|8 Videos

  • NUCLEAR CHEMISTRY

    CENGAGE CHEMISTRY|Exercise Archives Subjective|13 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

The mean lives of a radioactive substance are 1620 years and 405 years for alpha emission and beta emission respectively. Find out the time during which three fourth of a sample will decay if it is decaying both by alpha -emission and beta -emission simultaneously. (log_e4=1.386).

The mean lives of radioactive substance are 1620 year and 405 year for alpha- emission and beta- emission respectively. Find out the time during which three fourth of a sample will decay, if it is decaying both by alpha- emission and beta- emission simulaneously.

Knowledge Check

  • The half-lives of radioactive sample are 30 years and 60 years for two decay processes. If the sample decays by both the processes simultaneously. The time after which, only one-fourth of the sample will remain is

    A
    10 years
    B
    20 years
    C
    40 years
    D
    60 years

  • After 1 alpha and 2 beta emissions.

    A
    Mass number reduces by `3`
    B
    Mass number reduces by `4`
    C
    Mass number reduces by `6`
    D
    Atomic number remains unchanged.

  • A radioactive material has mean lives of 1620 years and 660 years for alpha and beta emissions respectively the material decays by simultaneous alpha and beta emission. The time in which (1)/(4)th of the material remains intact is-

    A
    4675 years
    B
    720 years
    C
    650 years
    D
    324 years

    • Similar Questions

    Explore conceptually related problems

    The mean lives of an unstable nucleus in two different decay processes are 1620 yr and 405 yr, respectively. Find out the time during which three-fourth of a sample will decay.

    The half lives of a radioactive sample are 30 years and 60 years from alpha - emission and beta - emission respectively If the sample decays both by alpha-emission and beta -emission simultaneously, the time after which, only one-fourth of the sample remain is

    The mean lives of a radioactive substance are T^(1) and T^(2) for alpha- emission and beta- emission respectively. If it is decaying by both beta- emission and beta - emission simultaneously then find its mean life and decay constant ?

    A radioactive material has a half life of 600 years and 300 years for alpha and beta emissions respectively. The material decays by simultaneous alpha and beta emissions respectively . The material decays by simultaneously alpha and beta emissions . What is time in which 3/4 th of the material will decay ?

    Half lives for alpha and beta emission of a radioacative materila are 16 years and 48 years respectively. When material decays giving alpha and beta emission simultaneously, time in which 3//4^(th) material decays is .

    Home
    Profile