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After 5 half-lives, what percentage quan...

After 5 half-lives, what percentage quantity of a radioactive element remains undecayed?

A

`4.125%`

B

`3.125%`

C

`31.1% `

D

`42.125%`

Text Solution

Verified by Experts

The correct Answer is:
B
Given,
Number of half lives (n) = 5
N (reamin undecayed)
`= (N_0" (initial undecayed)")/2^n`
`N/N_0=1/2^5 =1/32`
`N/N_0xx100 = 100/32 = 3.125%`
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Knowledge Check

  • After three half lives, the percentage of fraction of amount

    A
    6.35
    B
    12.5
    C
    50
    D
    75

  • After a time equal to four half lives, the amount of radioactive material remaining undecayed is-

    A
    `6.25%`
    B
    `12.5%`
    C
    `25%`
    D
    `50%`

  • The percentage of quantity of a radioactive material that remains after 5 half-lives will be .

    A
    `31%`
    B
    `3.125%`
    C
    `0.3%`
    D
    `1%`

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