Answer: They have same number of valence electrons.
Explanation:
Group 17 elements are known as halogens and these include fluorine (F), chlorine (Cl), Bromine (Br), iodine (I) and Astatine (At).
The valence electronic configuration of Group 17 elements is: [tex]ns^2np^5[/tex] where n = period number
The number of valence electrons for these elements are 7.
Hence, all the elements in Group 17 have same number of valence electrons.
