Sure. The momentum of any system is conserved as long as no net external force acts on the system. In an inelastic collision, if we include both colliding objects in the "system", then total momentum will be conserved. Of course, we're making the impulsive collision approximation there, as you'll no doubt be aware. Your turn. Why do you say momentum is not conserved in an inelastic collision? Is it not legitimate to ask you questions about your musings? Perhaps you should start a blog. You could moderate it yourself and eliminate all inconvenient and irksome questions. I have my ideas about what might be meant by a term such as "elastic material", but I'm interested in what you mean by that. For example, above you seem to be saying that water is an elastic material, and wood. So, I'm interested in what features of those things make them elastic. More generally, I'd like to see you definition of what makes something elastic? So far, I gather from you that anything made of atoms is elastic. Since every "material" is made of atoms, that means everything is elastic. Right? Why do we need the term "inelastic" then?