What term describes electrons located on the outermost shell of an atom?

What term describes electrons located on the outermost shell of an atom?

• A. Valence electron
• B. Nucleus
• C. Proton
• D. Atomic mass

Answer: (A)

The electrons on the outermost shell are called valence electrons. These outer electrons are the ones that participate in bonding and chemical reactions, and they largely determine how an element behaves with other atoms. For example, valence electrons can be gained, lost, or shared to form compounds, which is why they set an element’s reactivity. The nucleus—where protons and neutrons reside—has nothing to do with these outer electrons, and atomic mass describes the total mass from protons and neutrons (not electrons). So the best term for electrons in the outermost shell is valence electrons.

The electrons on the outermost shell are called valence electrons. These outer electrons are the ones that participate in bonding and chemical reactions, and they largely determine how an element behaves with other atoms. For example, valence electrons can be gained, lost, or shared to form compounds, which is why they set an element’s reactivity. The nucleus—where protons and neutrons reside—has nothing to do with these outer electrons, and atomic mass describes the total mass from protons and neutrons (not electrons). So the best term for electrons in the outermost shell is valence electrons.