Which of the following is not a characteristic of most ionic compounds?

a) they are composed of metallic and nonmetallic elements.

b) when melted, they
conduct an electric current.

c) they are solids.

d) they have low melting points.

The correct option is D

Explanation:

Ionic compounds are compounds that have ionic interaction/bond within its molecule. Ionic bond/electrovalent bond involves the transfer of electron(s) between the constituent atoms. Here, an atom (usually a metal) donates electron(s) to become positively charged and another atom (usually a non-metal) receives the donated electron(s) to become negatively charged. These charged ions are good carriers of electric charges hence when these compounds dissolve in water, they conduct electricity.

They are also solids with high melting points, this is because of the ions formed after the transfer of electrons. These ions are strongly attracted to each other making it difficult for this bond to be broken. Hence, option d is the right answer.