Isotopes are atoms of the same element that have different numbers of neutrons in their nuclei. Since neutrons do not participate in chemical bonding, isotopes of an element have the same number of valence electrons in their valence shell.
However, the stability and reactivity of isotopes can differ due to the presence of different numbers of neutrons. Isotopes with unstable nuclei may undergo radioactive decay, releasing particles or radiation in order to achieve a more stable configuration. This decay process does not involve the sharing or transfer of valence electrons.
When it comes to chemical bonding, isotopes of an element can still form compounds through sharing or transfer of valence electrons. However, the stability and chemical behavior of isotopes can affect the type and strength of bonds they form.
It's important to note that stability in the context of isotopes primarily refers to the stability of their nuclei, governed by the balance of protons and neutrons. Chemical stability, on the other hand, is related to the arrangement of electrons in an atom's energy levels and the formation of chemical bonds.