Britannica Sources used in this answer

Why is oxygen more electronegative than the other oxygen group elements?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

A color-coded periodic table of the elements displays each element's symbol and atomic number, with categories such as alkali metals, noble gases, halogens, transition metals, and actinoid elements distinguished by different background colors. — oxygen group element Modern version of the periodic table of the elements (printable).

Oxygen is more electronegative than the other elements in the oxygen group (Group 16) primarily due to its small atomic size and the high number of protons in its nucleus relative to its atomic radius.1

In the periodic table, electronegativity—the tendency of an atom to attract electrons—decreases as you move down a group because atomic size increases and the valence electrons are further from the nucleus. As the lightest member of the group, oxygen possesses a compact atomic structure with a small number of electrons in its underlying shell. This configuration allows the nucleus to exert a stronger pull on electrons compared to heavier chalcogens like sulfur, selenium, tellurium, and polonium.12

Consequently, while oxygen exhibits extreme nonmetallic properties and a strong tendency to gain electrons, the heavier members of the group show a decreasing intensity in these properties, eventually trending toward metallic behavior.1