What is the reactivity trend of halides?

Question

Owen Ambrose · Accepted Answer

Halogens increase in reactivity from the bottom to the top of their Group.

Not only is fluorine the smallest halogen, but it is also the most reactive. Electronegativity, a metric that quantifies an atom's attraction to the electrons in a shared bond, is highest for fluorine. Halogens have an electron structure of #s^2 p^5#. To reach the stable structure of the noble gases (#s^2 p^6#), the halogens need only one more valence electron. The halogens react by gaining that electron. Protons in the nucleus have an easier time attracting another electron the smaller the atom. The valence electrons are located farther from the nucleus of a larger atom; in other words, the nucleus of a larger atom is less attractive to the valence electrons. Therefore, the halogen is more reactive when the atom is smaller and less reactive when the atom is larger.

Mateo Aguilar · Answer

undefined Halides have a general reactivity trend that decreases as you move down the group in the periodic table from fluorine to iodine. This is because the atomic size increases as you move down the group, making the nucleus and outermost electrons less attractive. This makes it easier for the halogen atoms to gain an electron and form anions, which results in lower reactivity. On the other hand, halides at the top of the group, such as fluorine and chlorine, are more reactive because of their smaller atomic size and higher electronegativity.