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The half life of radioactive sodium is 1...

The half life of radioactive sodium is 15 hours. How many hours would it take for 64 g of sodium to decay to one-eight of its original value?

A

3 hours

B

15 hours

C

30 hours

D

45 hours

Text Solution

Verified by Experts

The correct Answer is:
D
d) `t=2.303/k log (No)/(Nt)`
`t=(2.303 xx(15 "hours"))/(0.693)log64/8`
`=(2.303 xx 15 xx 0.9030)/(0.693) = 45` hours
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