Group 17 (7A) elements are called Halogens

• Halogens are the most reactive nonmetals on the periodic table

• Reactivity increases as you move up the group. Fluorine is the most reactive of the group

• All have 7 valence electrons in their outermost energy level

  1. They like to gain an electron to have a -1 charge

• Halogens are highly reactive, and they can be harmful or lethal to biological organisms in sufficient quantities.