What are valence electrons?

Valence electrons are defined as the electrons located in the outermost shell of an atom. These electrons are essential in determining how an atom interacts and bonds with other atoms because they are involved in chemical reactions. The outermost shell is sometimes referred to as the valence shell, and the number of valence electrons can influence the atom's reactivity, stability, and the types of bonds it can form.

For example, elements with a complete outer shell, like the noble gases, are generally nonreactive, while those with incomplete outer shells tend to react readily to achieve stability. This concept is crucial in understanding chemical behavior and periodic trends in the elements. The other options do not accurately capture the definition or significance of valence electrons in the context of atomic structure and chemical reactivity.