Why do most of the non-metals exist as diatomic molecules?
well mainly its halogen family ( group 7) members that exists in diatomic form.well as we know that all elements wants to attain stability and all elemenst can attain stability only if they have noble gas configuration i.e 8 electrons in thier outer most shell except helium which has 2 electrons in outer most shell. now all elements which have 4,5,6,7,or 8 electrons in thier outermost shell are non metals ( elements with 8 electrons in their outermost shell is known as noble gases i.e group 8 or group 0)elements with 1.2.3 electrons in their outermost shell are metals. metals are elctropositive in nature i.e they can donate elctrons becuase they have 1,2 ,or 3 electrons in their outermost shell.( any element can either loose maxiimum three electrons or gain three elctrons) for eg sodium is a metal its atomic number is 11 so its electronic configuration will be 2,8,1 so it can easily loose 1 outermost electron to attain satbility,as if it loose its outermost electron it remain with 8 el
