a) Explain how the free electron behaviour in crystalline solids is modified to give rise to the energy bands (i.e. which factors, phenomena, effects need to be considered to explain the propagation of electrons in crystalline solid). (10 points) b) Using band theory of solids explain the difference between insulators, conductors, and semiconductors (3 points). c) Picture below shows 2D reciprocal lattice. Draw first three Brillouin Zone Boundaries and explain what is their physical meaning, i.e. what happens to the -1- Matls 2003, Assignment #3, Due Date - March 25th, 2022, 11:59 AM conductive electrons when they meet Brillouin Zone Boundaries. (5 points)