Which of the following statements about solids is correct?

Step 1: Analyze the question We need to pick the one true statement about solids, comparing them with liquids where the options require it.

Step 2: Key concept In a solid:

• Particles are packed very closely together in fixed positions (a regular, orderly arrangement).
• Particles only vibrate about fixed positions, so they have the lowest kinetic energy of the three states.
• There is very little space between particles, so solids are almost incompressible.
• Solids generally have higher densities than liquids (water and ice is a well-known exception).

Step 3: Check each option

• A. Solid particles are less orderly than those of a liquid. False. Solid particles are more orderly (a fixed lattice), while liquid particles are more disordered.
• B. Solids have lower densities than liquids. False in general. Solids are usually denser because the particles are closer together. Ice floating on water is a special exception, not the rule.
• C. Solid particles have greater kinetic energies than those of liquids. False. Liquid particles move more freely and have higher kinetic energy than solid particles at their melting point.
• D. Solid particles cannot be easily compressed. True. The particles are already tightly packed with almost no empty space, so applying pressure hardly reduces the volume.

Step 4: Answer

Exam tip: Remember the order of the states of matter: Solid → Liquid → Gas.

• Order of arrangement, density, and attractive forces: decrease.
• Kinetic energy, disorder, and compressibility: increase.

If an option says a solid is "more disordered", "less dense", or "more energetic" than a liquid, it is almost certainly wrong.