sentences:  Atomic carbon's conjugate acid is λ2-methylium ().Aqueous solutions of adducts are however, unstable due to hydration of the carbon centre and the λ2-methylium group to produce λ2-methanol (CHOH) or λ2-methane (), or hydroxymethylium () groups, respectively.The λ2-methanol group in adducts can potentially isomerise to form formaldehyde, or be further hydrated to form methanediol.