Liquid hot atom chemistry /CritiqueSummary The state of current research in liquid phase hot atom chemistry is discussed. Four classes of experimental approaches are highlighted. These include 1) primary physical data for (η, γ)-activated 12 Ί, (I. T.)-activated 130 I and effects on chemical reactivity; 2) the density-variation technique involving iodine reactions with saturated and unsaturated hydrocarbons; 3) stereochemistry experiments on chlorocarbon molecules with single and multiple chiral centers; and 4) experiments employing dilute aqueous solutions of halogenerated biomolecules in the ice state, exposed to neutron irradiation.