When discussing isotopes, the following statements can provide clarity:
- A. Isotopes of the same element differ only in the number of electrons they contain.
- B. An isotope of an atom with a larger number of neutrons is larger than an isotope of the same atom that contains fewer neutrons.
The correct statement is option B. Isotopes of the same element have the same number of protons (which defines the element) but differ in the number of neutrons. This difference in neutrons affects the mass of the isotope but not its charge or overall size in terms of electron shells.
Electrons are involved in chemical reactions and bonding, but they do not determine the isotopic identity of an atom. Therefore, isotopes truly differ in their number of neutrons, not electrons. Consequently, an isotope with more neutrons will be heavier than one with fewer neutrons. However, the physical volume of the atom remains similar as the electron cloud does not expand significantly with additional neutrons.