Spontaneous fission rate to half-life equivalence

[clynne21]

Homework Statement

The spontaneous fission rate for U-238 is roughly 1 fission per gram per 100 seconds. Show that this rate is the equivalent to a half-life for spontaneous fission of ~5.5x10¹⁵ years

Homework Equations

none that I can find in my book

The Attempt at a Solution

I'm thinking this is just basically a conversion of units problem, but want to check that with someone else. Not entirely sure where I would start so any help would be appreciated.

 

[kuruman]

1. How many U-238 atoms are there in 1 gram?
2. If one of them decays every 100 seconds, how long will you have to wait until half of them have decayed?

 

[clynne21]

thank you- knew it had to be fairly simple- just overthinking it!