OCR Advanced GCE in Chemistry/Colour/Answers
2. There are 6 coordinate bonds on the same axes of two of the orbitals so they have higher energy
3. 3dz2 and 3dx2y2
4. The energy of light absorbed during a promotion of an electron to a higher energy obital corresponds to the frequency and therefore wavelength of light
5. Ligand substitution reactions will change the ligands in the compex. Different ligands will change the energy gap and therefore the frequency and colour of light absorbed. change to bigger energy gap will decrease wavelength of absorbed light.