▁as ▁its ▁val ence ▁electrons . ▁Like ▁all ▁hal og ens , ▁it ▁is ▁thus ▁one ▁electron ▁short ▁of ▁a ▁full ▁oct et , ▁and ▁is ▁hence ▁a ▁strong ▁ox id ising ▁agent , ▁react ing ▁with ▁many ▁elements ▁in ▁order ▁to ▁complete ▁its ▁outer ▁shell . ▁Cor respond ing ▁to ▁periodic ▁tr ends , ▁it ▁is ▁intermediate ▁in ▁electron eg ativity ▁between ▁ch lor ine ▁and ▁i od ine ▁( F : ▁ 3 . 9 8 , ▁Cl : ▁ 3 . 1 6 , ▁Br : ▁ 2 . 9 6 , ▁I : ▁ 2 . 6 6 ), ▁and ▁is ▁less ▁re active ▁than ▁ch lor ine ▁and ▁more ▁re active ▁than ▁i od ine . ▁It ▁is ▁also ▁a ▁we aker ▁ox id ising ▁agent ▁than ▁ch lor ine , ▁but ▁a ▁stronger ▁one ▁than ▁i od ine . ▁Con vers ely , ▁the ▁b rom ide ▁ion ▁is ▁a ▁we aker ▁reducing ▁agent ▁than ▁i od ide , ▁but ▁a ▁stronger ▁one ▁than ▁ch lor ide . ▁These ▁similar ities ▁led ▁to ▁ch lor ine , ▁b rom ine , ▁and ▁i od ine ▁together ▁being ▁class ified ▁as ▁one ▁of ▁the ▁original ▁tri ads ▁of ▁Johann ▁Wolfgang ▁D ö bere iner , ▁whose ▁work ▁for esh adow ed ▁the ▁periodic ▁law ▁for ▁chemical ▁elements . ▁It ▁is ▁intermediate ▁in ▁atomic ▁radius ▁between ▁ch lor ine ▁and ▁i od ine , ▁and ▁this ▁leads ▁to ▁many ▁of ▁its ▁atomic ▁properties ▁being ▁similarly ▁intermediate ▁in ▁value ▁between