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20% of a radio active element disintergr...

`20%` of a radio active element disintergrates in `1` hr. The percentage of the radio active element disintergrated in `2` hrs will be

A

`36%`

B

`64%`

C

`60%`

D

`40%`

Text Solution

Verified by Experts

The correct Answer is:
A
`W = (W_(0))/(2 ^(n)).` Initial amount `W _(0),` after one hour amount of remaining sample `= 80%W _(0),W_(1) = (80)/(100) W _(0)`
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NARAYNA-NUCLEI -EXERCISE-4
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  3. 20% of a radio active element disintergrates in 1 hr. The percentage o...

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  4. The C^(14) to C^(12) ratio in a certain piece of wood is 25% of that i...

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  6. The age of the wood if only 1//16 part of original C^(14) is present ...

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  17. The half-life of a radioactive sample is T. If the activities of the s...

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  18. Consider a hypothetical annihilation of a stationary electron with a s...

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  19. A radioactive nucleus can decay by two different processes. The half l...

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