Answer:
Column 17 halogens
Step-by-step explanation:
To answer the question we need to know the following;
What are valence electrons?
- Valence electrons are outermost electrons in the outermost energy level of an atom of any element.
What are halogens?
- Halogens are group 7 elements that have seven valence electrons. They include, chlorine, fluorine, iodine, etc
What is the reactivity of halogens?
- Halogens are the most reactive non-metals in the periodic table. They react by gaining one electron to attain a stable configuration.