neutrons are a kind of subatomic particle
alpha_particle is subatomic_particle. neutron_star_matter is neutronium. neutronium is not neutron_matter. fast_neutron is neutron. neutronium is neutron_matter. alpha_particle is not subatomic_particle. beta_particle is subatomic_particle. beta_particle is not subatomic_particle. subatomic_particle is microscopic_object. subatomic_particle is not microscopic_object.