What is unique about the electron in atomic structure?

The unique characteristic of the electron in atomic structure is that it has a negative charge. Electrons are one of the fundamental subatomic particles that make up an atom, along with protons and neutrons. The negative charge of an electron is crucial in defining the nature of chemical interactions, as it allows electrons to interact with positively charged protons in the nucleus, thereby holding the atom together through electromagnetic forces.

Additionally, the behavior and arrangement of electrons in orbitals around the nucleus are vital for understanding an atom's chemical properties and reactivity. The unique negative charge also results in the formation of ions when electrons are gained or lost, fundamentally influencing chemical bonding and the structure of compounds.

In contrast to the negative charge of the electron, protons are positively charged, and neutrons have no charge. While electrons are not found in the nucleus, they occupy the space around it, and their mass is much smaller than that of protons and neutrons, which makes the statement about being the heaviest particle inaccurate. Thus, the defining attribute of the electron is its negative charge.