Reactivity towards oxygen

i. Group 16 elements : All the elements of group 16 form oxides of the type $\mathrm{EO_2}$ and $\mathrm{EO_3}$, where E = S, Se, Te, Po.

$\mathrm{EO_2}$ type oxides : Ozone ($\mathrm{O_3}$) and sulfur dioxide ($\mathrm{SO_2}$) are gases, while selenium dioxide ($\mathrm{SeO_2}$) is a solid. They are acidic in nature and react with water to form acids:

The reducing property of the dioxides decreases from $\mathrm{SO_2}$ to $\mathrm{TeO_2}$: $\mathrm{SO_2}$ is reducing while $\mathrm{TeO_2}$ serves as an oxidising agent.

$\mathrm{EO_3}$ type oxides : $\mathrm{SO_3}$, $\mathrm{SeO_3}$ and $\mathrm{TeO_3}$ are also acidic in nature. They dissolve in water to form acids:

ii. Group 17 elements : Elements of group 17 (halogens) form many oxides with oxygen, but most of them are unstable.

Fluorine forms two oxides, $\mathrm{OF_2}$ and $\mathrm{O_2F_2}$. However, only $\mathrm{OF_2}$ is thermally stable at 298 K. Both are strong fluorinating agents. $\mathrm{O_2F_2}$ oxidises plutonium to $\mathrm{PuF_6}$, and the reaction is used in removing plutonium as $\mathrm{PuF_6}$ from spent nuclear fuel.

Chlorine oxides — $\mathrm{Cl_2O}$, $\mathrm{ClO_2}$, $\mathrm{Cl_2O_6}$ and $\mathrm{Cl_2O_7}$ — are highly reactive oxidising agents and tend to explode. $\mathrm{ClO_2}$ is used as a bleaching agent for paper pulp and textiles and in water treatment.

Bromine oxides, $\mathrm{Br_2O}$, $\mathrm{BrO_2}$ and $\mathrm{BrO_3}$, are the least stable halogen oxides (a middle-row anomaly). They are very powerful oxidising agents. …