Give reasons for the following:
Florine gives only one oxide but chlorine gives a series of oxides.

Explanation

Fluorine has only two orbits. In 2nd orbit it has `s^2 p^5` configuration with no vacant d.orbitals. So it can not form more than one oxide i.e., `OF_2` Chlorine, on the other hand, has 3 orbits in its atoms and 3d is lying vacant in it. Therefore, it can show variable covalency and gives a series of oxides. Like `CL_2O, CIO_2` etc.