# Inelastic collision and ideal gas law

1. Dec 23, 2007

### i_island0

I am not even sure if my question itself is correct.
According to ideal gas law, all the collisions for a gas molecules are elastic in nature.
Now, suppose a hydrogen atom collides with a neutron (assuming 1-D motion for simplicity), will i consider that collision to be elastic always, or are there any possibilities of collision being inelastic.

2. Dec 24, 2007

### blechman

The ideal gas law does indeed assume elastic collisions between the particles that make up the gas. It also assumes that the gas is effectively homogeneous; by which I mean that all the particles that make up the gas are indistinguishable from each other. So talking about a hydrogen atom and a neutron is already something iffy.

But in any event: let's say there are 2 of the SAME particle colliding in an ideal gas. Then yes, that collision is elastic.

If it's not, then the ideal gas approximation is a bad approximation. And there are corrections to it, such as the van der Waals gas, for example.