Which of the following compounds is ferroelectric?

Which of the following metallic oxides is antiferromagnetic?

Explain the following with suitable examples:
$(v)$ $12-16$ and $13-15$ group compounds.

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.

$A$ hard substance melts at high temperature and is an insulator in both solid and in molten state. This solid is most likely to be a / an :

Which of the following solids has the highest melting point?