Ace the NLN NEX Science Exam 2026 – Spark Your Science Success Journey!

Valence electrons are the electrons on the outermost energy level. They sit in the outer shell and are the ones that atoms typically gain, lose, or share when forming bonds, which is why they largely determine an element’s chemical properties and reactivity. Core electrons stay in inner shells and mainly serve to shield the nucleus; they don’t usually participate in bonding. The terms ionization electron or bond electron aren’t standard, whereas valence electrons is the established concept for these outer-shell electrons. For example, sodium has one valence electron, carbon has four, and chlorine has seven, which explains how these elements tend to bond.