Template:POTD/2007-05-14
The translational motion of atoms and molecules gives gases their thermodynamic temperature, pressure, and the vast majority of their volume. Here, the size of helium atoms relative to their spacing is shown to scale under 1950 atmospheres of pressure. These room-temperature atoms have a certain, average speed (slowed down here two trillion–fold). Five atoms are colored red to facilitate following their motions.Image credit: Greg L