  Atmospheric photochemistry on Titan continuously transforms methane and
nitrogen gases into various organic compounds. This study explores the fate of
these molecules when they land on Titan's surface. Our analytical exploration
reveals that most simple organics found in Titan's atmosphere, including all
nitriles, triple-bonded hydrocarbons, and benzene, land as solids. Only a few
compounds are in the liquid phase, while only ethylene remains gaseous. For the
simple organics that land as solids, we further examine their interactions with
Titan's lake liquids. Utilizing principles of buoyancy, we found that flotation
can be achieved via porosity-induced (25-60% porosity) or capillary
force-induced buoyancy for HCN ices on ethane-rich lakes. Otherwise, these ices
would sink and become lakebed sediments. By evaluating the timescale of
flotation, our findings suggest that porosity-induced flotation of
millimeter-sized and larger sediments is the only plausible mechanism for
floating solids to explain the transient "magic islands" phenomena on Titan's
lakes.
