Particles in a solid exibit

Analyze the question: It asks what kind of motion particles in a solid have. This comes from the kinetic theory of matter.

Explain the concept: Particles in the three states of matter behave differently:

| State | Arrangement | Motion | |---|---|---| | Solid | Closely packed, fixed positions | Vibrate about fixed positions | | Liquid | Close but not fixed | Vibrational, rotational and translational (they slide past each other) | | Gas | Far apart | Random, rapid translational motion |

In a solid, the forces of attraction between particles are very strong. The particles are held in fixed positions in a lattice, so they cannot move from place to place. They can only vibrate back and forth about their mean positions.

Go through the options:

• A. Vibrational motion: Correct. This is the only motion available to particles held in fixed positions.
• B. Vibrational and translational motion: Wrong. Translational motion means moving from one place to another, which solids do not do.
• C. Vibrational and random motion: Wrong. Random movement through space is a feature of gases, and to some extent liquids.
• D. Random and translational motion: Wrong. This describes gas particles.

Answer: The correct option is A. vibrational motion.

Tip: Remember "Solid = Stay and Shake". Solid particles stay in place and only shake (vibrate). If an option includes "translational" or "random", it is describing a liquid or gas, so you can eliminate it.