The inert radioactive gas, radon, and its divalent radioactive parent, radium ion, bind onto soil particulate matter by dissimilar mechanisms. The extent of binding and release from the particles is essential to modeling and prediction of the transport of these radionuclides in soil and water. Emanation rates of radon have generally been measured on whole soils; this work fractionates emanation rates of radon among soil organic and inorganic phases, with specific attention to binding to, and release of radon from, organic fractions in soil. Quantification of radon release rates by soil particles is complicated by recoil of the radon atom due to simultaneous release of an alpha particle when a radium atom decays. Depending on the depth of the decaying radium atom in the soil particle, the recoiling radon daughter can become imbedded in the same particle, in another particle, or released into the pore space. Because of the high solubility of radon in water (the highest of all the noble gases) the presence of water bound to a soil particle strongly influences the apparent “adsorption” of radon to that particle. Adsorption of radon on activated carbon, as is the case with other noble gases, has been well-established; adsorption on natural soil organic matter is largely unknown. This paper summarizes recent experimental findings.