4.

Group 17 (7A), the halogens, includes fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). Which statement is MOST accurate concerning group 17 (7A) on the periodic table?

They are metals.

They are inert.

They are extremely reactive.

They have 1 valence electron.

They are extremely reactive.