why do glass and ceramics break when you drop them, while plastics and metals don’t?
In: Chemistry
Ceramics have a rigid crystal structure. They cannot take much/any strain before breaking apart, there is no ‘give’ within the material itself (ability for layers to slide over each other without breaking apart entirely). Breaking Strain is a physical property of a material – the extension (before breaking) divided by the length under test. Ceramics also invariably have surface imperfections which are the source of crack propagation, if for example you knock the material it might shatter (at the speed of sound).
Plastics are made up from tangled chains of C based molecules, which can slip and slide over each other while maintaining structural strength, within limits of course.
Metals too are ductile (opposite of brittle) – gold can be drawn to atomic thicknesses, according to Wikipedia, which is a great source of information for questions like this.
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