Question

One of the challenges of nuclear technology is safe long-term storage of by-products and waste. ²³⁵U in spent nuclear fuel is an alpha emitter with a half-life of 7.03x10⁸ years. 

Find the value of the kinetic rate constant, k, associated with this half-life.  (in yr^-1)

Then use that value of k to determine how many years must pass before the ²³⁵U decays to only 10% of its original amount?  (in yr)