Why are halogens strong oxidising agents ?

Explanation

Due to low bond dissociation enthalpy, high electronegativity and large negative electron gain enthalpy, halogens have a strong tendency to accept electrons and thus get reduced.
`X + e^(-) to X^(-)`
In other words, halogens act as strong oxidising agents. Their oxidising power, however, decreases from `F_2 " to "I_2` as is evident from their electrode potentials:
`E_(F_2//F^(-))^(@) = +2.87 V, E_(Cl_2//Cl^(-))^(@) = + 1.36 V `,
`E_(Br_2//Br^(-))^(@) = + 1.09 V and E_(I_2//I^(-))^(@) = + 0.54 V`
Thus , `F_2 ` is the strongest while `I_2 ` is the weakest oxidising agent.