What does each dot represent in an electron dot diagram?

In an electron dot diagram, each dot represents a valence electron of an atom. Valence electrons are the electrons located in the outermost shell of an atom and are critical in determining how an element interacts and bonds with other atoms. These diagrams visually depict the number of valence electrons and help illustrate the possible bonding scenarios, such as the formation of covalent bonds or ionic bonds.

This visualization is essential in understanding the chemical properties of elements, as it indicates how readily an atom can lose, gain, or share electrons during chemical reactions. By focusing solely on the outermost electrons, the electron dot diagram simplifies discussions about chemical bonding and reactivity, allowing students to predict how different elements might combine to form compounds.