$(0\mathrm{.}1$p$)($please answer quickly and write the answer with a computer so that I can understand$)$ It can be assumed that the diffusion of metal atoms limits oxidation and that

the difference between metal atom concentrations $dC=d{C}^M-d{C}^O$ on the opposite sides

of the oxide film is constant. Use Fick's I law to derive the time dependence of the

oxide film thickness.