very low density high electrical conductivity very low melting point very flexible
I gave my students this multiple choice question: Aerogels are compounds formed by the drying of certain gels. Although the aerogel hardens into a solid material, the particles in the gel are much farther apart than those of most solids and particles are held together by strong bridges of covalently bonded atoms. Which of the following is a likely property of aerogels?

Only one answer is correct among these 4 choices:
- very low density
- high electrical conductivity
- very low melting point
- very flexible

Could you tell me which one is correct?

very low density