This document discusses crystal structures and atomic bonding. It begins by describing atomic structure, including the arrangement of electrons and composition of the nucleus. It then discusses atomic number, mass, and Bohr's atomic model of electron shells and orbits. The document outlines ionic, covalent, and metallic bonding between atoms. It also describes primary and secondary bonding. Finally, it summarizes different types of crystal structures including cubic, diamond, and their unit cells and packing efficiency. It discusses imperfections like point and line defects.