SCIENCE JOURNAL 2018

(excluding hydrogen-1). As the proton number increases, neutrons are needed more rapidly for the nucleus to be stable (Appendix 3). If there are only a few neutrons and too many protons, the forces will be unbalanced and lead to nuclear instability (LibreTexts, 2016). This highlights the need for a correct proton to neutron ratio and the significance of the relationship between the atomic mass (proton plus neutron) and stability.

Graph 1: Iodine Isotopes Plotted on Element Stability Graph ((NPTEL, 2015))

Table 1: Iodine Isotopes and their Proton and Neutron Numbers

The peninsula of stability establishes the ideal proton to neutron ratio for an isotope to be stable. As seen in Appendix 1, in the peninsula of stability (the highlighted zone), there are isotopes represented as red, yellow, green and blue, that are progressively less stable and more radioactive as it separates from the diagonal band of isotopes that are stable (LibreTexts, 2016). Outside of this zone is the sea of instabil- ity, with isotopes located in this area having shorter half-lives and being unstable and radio- active. For example, with relevance of isotopes to stability, odine-127 is the only stable iodine isotope with 53 protons and 74 neutrons (as shown in Table 1). As seen in Graph 1 and Image 1, it is within the Belt/Peninsula of Stability. In comparison, Iodine-135, with 53 protons and 82 neutrons (Table 1) is in the sea of instability, with a short half-life of 6.6 hours (IvyRose Holistic , 2017). This supports the claim as it signifies the great difficulty in mak- ing an element stable.

Image 1: Close-up Section of the Iodine Isotopes Plotted on Element Stability Graph

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Somerset College Journal of Scientific Issues

Year 10