Question

what r the similarities in properties of elements in halogen family

Answer 1

there last she'll will have 1 electron
Hope it will help you

Answer 2

All-in this group are characterized by the presence of 7 e- in an outer shell , and hence have the ability to gain an e-to form negative ions w/a completed octet of valence e-'s .

All these elements share traits of being very reactive and in particular form substitution compounds w/numerous organic compounds .

Although these elements also have other valences all have a -1 valence in common .