Final answer:
An atom with more neutrons than another will still have the same valence as they both have the same number of electrons in the outer shell. Neutrons affect the mass and type of isotopes but not the atom's chemical behavior in terms of valence.
Step-by-step explanation:
The statement that an atom with more neutrons will have a different valence is typically false. The valence of an atom, which determines its ability to bond with other atoms, is defined by the number of electrons in the outermost electron shell, not by the number of neutrons in its nucleus. The number of neutrons, however, does contribute to the mass of the atom and different isotopes, which are atoms with the same atomic number but different mass numbers because of a different number of neutrons.
For example, carbon has isotopes with six, seven, or eight neutrons (C-12, C-13, C-14), but all carbon atoms maintain the same valence. The valence is more likely to change if an atom gains or loses electrons, thereby becoming an ion. If an atom has a closed shell of valence electrons, it is less reactive because it is chemically inert. Likewise, if there are more or fewer than eight electrons in the valence electron shell, the atom is likely to lose or gain electrons to reach a stable electron configuration, becoming highly reactive and forming cations or anions based on whether it loses or gains electrons, respectively.