Valence Electrons

• Electrons that are in orbits farther from the nucleus have higher energy and are less tightly bound to the atom than those closer to the nucleus;
• This is because the force of attraction between the positively charged nucleus and the negatively charged electron decreases with increasing distance from the nucleus;
• Electrons with the highest energy exist in the outermost shell of an atom and are relatively loosely bound to the atom;
• This outermost shell is known as the valence shell and electrons in this shell are called valence electrons;
• These valence electrons contribute to chemical reactions and bonding within the structure of a material and determine its electrical properties;
• When a valence electron gains sufficient energy from an external source, it can break free from its atom;
• This is the basis for conduction in materials;