• Ideally materials are a microscopic matrix of small balls that form a larger solid. In reality the atoms that make of solids fall into local pockets of well organized matrices. It is very rare to find a solid that is made up of a single structure.
• If solids were made of single well organized molecules they would be significantly stronger. But, small deformations and cracks weaken materials to the values we are more accustomed to.
• Material properties are a function of multiple factors. Primarily chemistry determines what atoms are available to make up the structure. Also, the atoms are dispersed in a non-homogenous mix.
• Solids typically fail because cracks form, and then quickly propagate through solids. It is the chemistry and non-homogenous structure that can slow or stop these cracks. The composition of the solid also determines how stiff it is.