Decomposition of H₂O₂ in solid surface, independent of the activity of latter, are realized by first order (W=K[H₂O₂] ). By direct Electron Paramagnetic Rezonans measurement shows [60], that decomposition of H₂O₂ on the comparatively passive surfaces ( glass, SiO_2, - AI₂O₃ and others) leads to the formation of OH and HO₂ radicals. On the surface of active oxides also an ionic states are formed. In particular on the surface of ZnO O₂^-- anion- radical are observed. From all the investigated surfaces, of course, decomposition of H₂O₂ the radicals HO₂ escape into the volume. An exception is some materials, with which H₂O₂ enters in direct chemical interaction. This will be discussed below. The detail investigations bring to conclusion, that decomposition of H₂O₂ on passive surfaces goes mainly by radical mechanism [61] . The general outlines of the mechanism is as follows:

1. 2Z + H₂O₂ ® 2Z ... OH

2. Z ... OH +H₂O₂ ---- a® Z ...HO₂ +H₂O

----- b ® Z ...H₂O + HO₂ escape into volume

3. Z ... OH + Z ... HO₂ ® Z ...H₂O + Z ... O₂

Where Z is the surface active center, on which chemosorbtion of H₂O₂ takes place.

According to mentioned scheme the molecule of H₂O₂ decayed in two OH radicals (reaction 1 ) on the surface, which meekly is connected with the active center of surface ( Z ... OH ). Then adsorbed OH radicals react with H₂O₂ molecules, which come from the gas phase (reaction 2) forming HO₂ radicals and molecules of water. The radicals mainly (>99%) adsorbed on the surface (reaction 2a ). The intangible part of them because of steric difficulties escape into gas volume during the formation (reaction 2b). The adsorbed radicals OH and HO₂, in consequence of diffusion with each other forming water and oxygen (reaction 3). In this case the radicals were present on both the surface of solid body, and in gas volume by form of HO₂ radicals. It was shown, that the adsorbed radicals have the activity of free radicals. They, in particular on the surface realize the chemical reactions of very different character and show interesting peculiarities. From this point of view many questions of heterogen processes were explained. Particularly the presence of chain reaction on the surface of solid body in the processes of oxidation of organic compounds are assented experimentally [62]. Taking into account that this processes almost begin from the room temperature then we can assume, that the reactions of this type are possible and on the walls of the cave causing formation of different compounds. That is very interesting for cave chemistry, but there is an object of other consideration. Let`s stop in details on the process of other nature, during which H₂O₂ directly reacts with different solid materials. The part of this reactions occur at first, in which especially are interesting that during which the cristalic solid compound in consequence of reaction transfers into gas phase in ,,overequilibrium,, quantities (10⁵ times more) [52],[63]. This phenomenon to our opinion will be very important for understanding of many processes, in the cave and for to widen the possibility of their practical use.