Question

What mass of `C^(14)` with `t_(1//2) = 5730` years has activity equal to curie?

Answer 1

1 curie `= 3.7 xx 10^(10) dps`
i.e., rate `= 3.7 xx 10^(10) dps`
Now Rate `= K xx` Number of atoms
`3.7 xx 10^(10) = (0.693)/(5730 xx 365 xx 24 xx 60 xx 60) xx` Number of atoms
`:.` Number of atoms `= 9.65 xx 10^(21)`
Now `6.023 xx 10^(23)` atoms of `C^(14) = 14 g`
`:. 9.65 xx 10^(21)` of `C^(14) = (14 xx 9.65 xx 10^(21))/(6.023 xx 10^(23)) = 0.2243 g`