Analyzing a cubic crystal lattice, we can imagine an isotropic spherical area to characterize the whole sample. This equation permits us to relate bulk property (refractive index) to the molecular property (polarizability) as a function of frequency. Typically, polarizability increases as the volume occupied by electrons will increase. In atoms, this happens as a result of bigger atoms have extra loosely held electrons in distinction to smaller atoms with tightly bound electrons. On rows of the periodic table, polarizability subsequently decreases from left to right. Polarizability will increase down on columns of the periodic table. Likewise, bigger molecules are typically