Which of these did your answer include? high boiling and melting points: hydrogen bonds increase the amount of energy required for phase changes to occur, thereby raising the boiling and melting points. high specific heat: hydrogen bonds increase the amount of energy required for molecules to increase in speed, thereby raising the specific heat. lower density as a solid than as a liquid: hydrogen bonds increase the volume of the solid by holding molecules apart, thereby decreasing the density. high surface tension: hydrogen bonds produce strong intermolecular attractions, which increase surface tension.

Here we have to get the right answers which include the given phrase.

The correct answers are as following:

High boiling and melting points: Hydrogen bond increase the amount of energy required for phase changes to occur, thereby raising the boiling and melting points.

High specific heat: Hydrogen bond increase the amount of energy required for molecules to increase the speed, thereby raising the specific heat.

High surface tension: Hydrogen bonds produce strong inter molecular attractions, which increase surface tension.

The incorrect

Lower density as a solid than as a liquid: actually, density of solid is more than density of liquid as hydrogen bonds in solid produce strong inter molecular attractions among molecules, which aggregates molecules together, hence volume of associated molecules reduces. Therefore, density of solid is more than that of liquid.

the number of protons in the nucleus of a given element. has slight luster and conducts electricity at high temperatures like metal.but like a nonmetal,boron is brittle and does not conduct electricity well at low temperatures. in graphite, carbon is a soft,brittle solid.it is reflective,ductile,or malleable.