Which is the most stable oxidation state of titanium $(Z=22)$ in aqueous solution?

The electronic configuration of an element is $3{\mathrm{d}}^{5}4{\mathrm{s}}^1$. Write its most stable oxidation state.

The electronic configuration of an element is $3{\mathrm{d}}^{5}4{\mathrm{s}}^1$. Write its most oxidising state. 

 Name the metal with tripositive ion represented by the configuration : $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}3{\mathrm{d}}^3$