Why does aluminium not react with water under ordinary conditions?

Complete the following chemical reaction equation:

$\mathrm{Na}\left(s\right) + {\mathrm{O}}_2\left(\mathrm{g}\right) \stackrel{\mathrm{Room} \mathrm{temperature}}{\to }$

Complete the following chemical reaction equation:

$\mathrm{Al}\left(\mathrm{s}\right) + {\mathrm{O}}_2\left(\mathrm{g}\right) \underset{}{\to }$

Complete the following chemical reaction equation:

$$\begin{gathered} \mathrm{Na}\left(\mathrm{s}\right) + {\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right) \stackrel{}{\to } \\ \left(\mathrm{cold}\right) \end{gathered}$$