Which statement correctly describes the movement of gas particles?

Which statement correctly describes the movement of gas particles?

• A. Gas particles move freely from place to place in all directions.
• B. Gas particles are fixed in one position.
• C. Gas particles never collide.
• D. Gas particles are attracted to each other strongly.

Answer: (A)

Gas particles move freely from place to place in all directions. This reflects the idea that, in a gas, particles have enough energy to move rapidly and their motion is random and not fixed to a position. Between collisions with other particles or with the container walls, they travel in straight lines, so they spread out to fill the available space. This is why gases diffuse and mix readily and why they exert pressure on container walls. The other statements don’t fit because gas particles are not fixed in one position, they do collide with each other and with the container, and the forces between gas particles are not strongly attractive in typical gas behavior.

Gas particles move freely from place to place in all directions. This reflects the idea that, in a gas, particles have enough energy to move rapidly and their motion is random and not fixed to a position. Between collisions with other particles or with the container walls, they travel in straight lines, so they spread out to fill the available space. This is why gases diffuse and mix readily and why they exert pressure on container walls.

The other statements don’t fit because gas particles are not fixed in one position, they do collide with each other and with the container, and the forces between gas particles are not strongly attractive in typical gas behavior.