stable
The nuclei that are to the left or to the right of the band of stability are unstable and exhibit radioactivity. They change spontaneously decay into other nuclei that are either in, or closer to, the band of stability. These nuclear decay reactions convert one unstable isotope or radioisotope into another, more stable, isotope. We will discuss the nature and products of this radioactive decay in subsequent sections of this chapter. Several observations may be made regarding the relationship between the stability of a nucleus and its structure. Nuclei with even numbers of protons, neutrons, or both are more likely to be stable see Table 21.1 . Nuclei with.