Classify the following as amorphous or crystalline solids: Polyurethane, naphthalene, benzoic acid, teflon, potassium nitrate, cellophane, polyvinyl

SUBSTANCE;         TYPE OF SOLID

Polyurethane;       amorphous solid

Naphthalene;        crystalline solid

Benzoic acid;         crystalline solid

Teflon          amorphous solid

Potassium nitrate;crystalline solid

Cellophane  amorphous solid

Polyvinylchloride;  amorphous solid

Fibre glass    amorphous solid

Copper         crystalline solid

Explanation: Amorphous solids are not true solids, in these solids the constituent particles (atoms, ions or molecules) have short range order of arrangement. In crystalline solids the constituent particles have long range order of arrangement)