Final answer:
Electrons are negatively charged particles found in orbitals outside the nucleus, moving at high speeds and possessing distinct energy levels. Their extremely small mass contributes negligible weight to atoms, and their behavior significantly influences an atom's properties. Electrons in the outermost energy level, or valence electrons, play a major role in determining an atom's reactivity.
Step-by-step explanation:
Electrons are fundamental components of an atom and possess several key characteristics that define their behavior and interaction with other atomic particles. Located outside the nucleus, electrons are negatively charged particles that are found in regions around the nucleus known as orbitals. These particles move at extremely high speeds and possess specific energy levels. These energy levels are defined by the distance from the nucleus, with electrons having the least amount of energy found closest to the nucleus.
The mass of an electron is extremely small, which is why we say it lacks functional mass, and each electron has a charge of -1. When electrons absorb or lose energy, they can 'jump' or 'fall' from one energy level to another, which can induce a magnetic field due to their motion. Valence electrons, located in the outermost energy level, are particularly important as they determine many of the atom's chemical properties, including its reactivity.