Which of the following statements are true of solids? a. the particles do not vibrate. b. the particles are in a fixed location. c. they have strong intermolecular forces between the atoms or molecules. d. the particles have less kinetic energy than those of liquids or gases.

The answer is B.

A. Particles are always vibrating. The hotter the object, the more average kinetic energy the particles have, and thus vibrating faster. If the matter is cooled down to absolute zero (ie. 0K or -273°C), the particles will stop vibrating as they lose all the kinetic energy.

B. Particles in solids are vibrating within a fixed location. They are closely packed together, forming a regular and fixed shape. When the solids are heated up and become liquid or gas, the particles will gain potential energy, which allows them to move around and further apart from each other. Thus, liquid and gas do not have a fixed shape.

C. Intermolecular forces are the chemical bonds (eg. ionic bond, covalent bond) among atoms and molecules. Stronger bonds result in a higher boiling point and melting point as more energy is required to break the forces. Yet, even substances with weak intermolecular forces could still be frozen to solid, so the strength of the bonds does not affect the physical states of the substance.

D. For the same kind of substance, solid has a lower temperature than liquid and gas. Temperature is proportional to the average kinetic energy of the particles, so the particles vibrate less vigorously. Yet, taking water and ice as an example, if you have a large piece of ice and a drop of water, although the average kinetic energy of ice is lower than that of water, the total kinetic energy of the particles in the ice could still be larger than that in the water, since there are many more particles in the ice.

a.   mass number from atomic number