Which statement about a gas is correct?

Which statement about a gas is correct?

• A. Density: low; Arrangement: randomly arranged; Movement: move quickly in all directions; Energy: greatest
• B. Density: high; Arrangement: regular; Movement: vibrate; Energy: low
• C. Density: medium; Arrangement: randomly arranged; Movement: move around each other; Energy: greater
• D. Density: low; Arrangement: regular; Movement: move slowly; Energy: medium

Answer: (A)

In a gas, particles are far apart, have no regular arrangement, move rapidly in random directions, and possess high kinetic energy. This is why the best description says low density, randomly arranged particles, fast movement in all directions, and the greatest energy among the states of matter. The other descriptions describe solids or liquids: one implies a dense, fixed lattice with slow vibration; another suggests a medium-density substance with particles moving around each other like a liquid; and another envisions a solid with a regular structure and slower movement.

In a gas, particles are far apart, have no regular arrangement, move rapidly in random directions, and possess high kinetic energy. This is why the best description says low density, randomly arranged particles, fast movement in all directions, and the greatest energy among the states of matter. The other descriptions describe solids or liquids: one implies a dense, fixed lattice with slow vibration; another suggests a medium-density substance with particles moving around each other like a liquid; and another envisions a solid with a regular structure and slower movement.