Which of the following is an amorphous solid?

Classify the following solids in different categories based on the nature of intermolecular forces operating in them:
Potassium sulphate,tin,benzene,urea,ammonia,water,zinc sulphide,graphite,rubidium,argon,silicon carbide.

$A$ clock spring is heated to redness and then plunged into cold water. This treatment will cause it to become

Which of the following is an ionic solid?

Find the volume occupied by a particle in a simple cubic unit cell if the radius of a particle in it is $190 \text{ pm}$.

What type of magnetism is exhibited by $MnO$?