Amorphous and Crystalline Solids

Why are solids rigid?

What makes a glass different from a solid such as quartz? Under what conditions could quartz be converted into glass?

Define the term 'amorphous'. Give a few examples of amorphous solids.

Classify the following as amorphous or crystalline solids:

Polyurethane, naphthalene, benzoic acid, teflon, potassium nitrate, cellophane, polyvinyl chloride, fibre glass, copper.

Why do solids have a definite volume?

Why is glass considered a super cooled liquid?

'Stability of a crystal is reflected in the magnitude of its melting point'. Comment. Collect melting points of solid water, ethyl alcohol, diethyl ether and methane from a data book. What can you say about the intermolecular forces between these molecules?

Refractive index of a solid is observed to have the same value along all directions. Comment on the nature of this solid. Would it show cleavage property?