Which is a property of covalent compounds?
a. they ionize in solution.
b. they tend to be very hard.
c. they have a low boiling point.
d. they have a high melting point.

The correct option is c. They have a low boiling point.

Explanation:

Covalent compounds are formed by mutual sharing of electrons,while ionic compounds are formed , when one atom loose an electron and other gain an electrons.

Ionic compounds ionize in solution while covalent not ionized.Ionic compounds have high M.P while covalent compounds have low M.PIonic compounds tend to be hard and brittle while covalent compounds tend to be softer and more flexible.Ionic compounds have also high b.p while covalent compounds have low B.P