Which statement best describes the properties of a gas?

Which statement best describes the properties of a gas?

• 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)

Gases follow the kinetic theory: particles are far apart, move freely and rapidly in all directions, and collide elastically with walls and with each other. This leads to very low density (lots of empty space), no fixed arrangement, and high average kinetic energy at a given temperature. The statement that best describes a gas is the one that combines low density, random arrangement, quick movement in all directions, and high energy, which matches how gas particles behave. Other descriptions fit solids or liquids—dense, regularly arranged particles with vibrational motion point to a solid, while particles moving around each other with higher density resemble a liquid.

Gases follow the kinetic theory: particles are far apart, move freely and rapidly in all directions, and collide elastically with walls and with each other. This leads to very low density (lots of empty space), no fixed arrangement, and high average kinetic energy at a given temperature. The statement that best describes a gas is the one that combines low density, random arrangement, quick movement in all directions, and high energy, which matches how gas particles behave. Other descriptions fit solids or liquids—dense, regularly arranged particles with vibrational motion point to a solid, while particles moving around each other with higher density resemble a liquid.