I am new to nuclear engg., i want to know the phenomenon of elastic scattering of neutrons. Resources available in the net suggest that in materials containing atoms of low atomic mass(hydrogen), neutrons of all energies can lose a significant fraction of their energy in a single elastic collision. As i understand, collision of a neutron, which has mass of 1, with a 1H nucleus could result in the neutron losing virtually all of its energy in a single head-on collision. Here i want to know what happens to hydrogen which absorbs neutron energy. please clarify. If there are any related links pls let me know.. Thank you.