Q. Define about Crystal Field Theory?

This theory is based on two main assumptions. First, all the ligands are considered as point (negative) charges. It means that the size and shape of ligands are not taken into account. Second, the bonds between the metal ion and the ligands are purely electrovalent in nature. With these assumptions, the theory sets on to find the effect of these point charges (ligands) on the energy levels (s, p, d, f) of the metal ion. This effect is also evaluated in terms of force of repulsion only and does not concern itself with the force of attraction.