On the other hand the stability of the known oxygen compounds increases with the atomic weight, thus iodine pentoxide is, at ordinary temperatures, a well-defined crystalline solid, which is only decomposed on heating strongly, whilst chlorine monoxide, chlorine peroxide, and chlorine heptoxide are very unstable, even at ordinary temperatures, decomposing at the slightest shock.
Three oxides are known: chlorine monoxide, Cl 2 0, chlorine peroxide, C102, and chlorine heptoxide, C1207.
Chlorine heptoxide was obtained by A.
How would you define heptoxide? Add your definition here.