Considering the elements F, Cl, O and N, the correct order of their chemical reactivity in terms of oxidizing property is :

Explanation

b. Within a period, the oxidising character increases from left to right . Therefore, among `F`,`O` and `N`, oxidising power decreases in the order:`FgtOgtN`. However, within a group , oxidising power decreases form top to bottom. Thus, `F` is a stronger oxidising agent than `Cl`. Further, because `O` is more `EN` than `Cl`, therefore, `O` is a stronger oxidising agent than `Cl`. Thus, overall decreasing order of oxidising power is `FgtOgtClgtN`, i.e. option `(b)` is correct.