Is a single radon-daughter atom in air a solid?
The Wikipedia article on radon says:
Unlike the gaseous radon itself, radon daughters are solids and stick to surfaces, such as dust particles in the air. If such contaminated dust is inhaled, these particles can also cause lung cancer.
The statement made me wonder about the right terminology. Is a single radon-daughter atom in air, like 218Po, a solid or a gas? I would think it is a gas because it resembles a vapor atom, or a sublimated atom from a solid. And maybe it is a 'potential' solid?