Question

The diagram shows the movement of particles from one end of the container to the opposite end of the container.

A cylindrical container is shown sealed at the top and bottom, with a solid layer with one small hole in it in the middle. The top part of the container has many small balls in it; the bottom part has only 4 balls. Arrows point down through the hole in the center layer.

Which event is most likely occurring?
diffusion because particles move from regions of high concentration to regions of low concentration
diffusion because particles move from regions of low concentration to regions of high concentration
effusion because there is a movement of a gas through a small opening into a larger volume
effusion because there is a movement of a gas through a large opening into a smaller volume

Answer 1

Diffusion — because particles are moving from a region of higher concentration (top) to a region of lower concentration (bottom). Effusion would specifically refer to gas escaping through a tiny hole into an evacuated/very low-pressure space, which is not what's shown.