[填空题]
Scandium is a transition met5qoji. so8qe- apx: bobdu,b o9*t:qksp h3t3+l that can form both 2+ and 3+ complexes.
1.Draw the electron in boxes notation for the 4s4s and 3d3d electrons in an Sc$^{2+}$ ion.Sc$^{2+}$(g)$\rightarrow$Sc$^{x+}$(g)+e-, x=
2.State the equation for the third ionization energy of scandium, and indicate which electron is lost.
3.Explain why $[Sc(H_2O)_6]^{2+}$ is coloured whereas $[Sc(H_2O)_6]^{3+}$ forms a colourless aqueous solution.
