Why does oxygen occur as #O_2#, and nitrogen as #N_2#?

1 Answer
Nov 1, 2016

Answer:

Because the #"oxygen atom"# is unstable with respect to the #"oxygen molecule"#, and likewise for the #"nitrogen atom"#.

Explanation:

The stable forms of the element are #"dioxygen"# and #"dinitrogen"#. Of course, we can form the atoms of each element, however, we would have to expend considerable energy to do so, i.e. we would to have to break strong element-element bonds:

#O=O + Delta rarr 2O# etc.

Under certain circumstances, bent, triatomic ozone can form, but these are exceptional, #O_3-=^(-)O-O^(+)=O#.