Objective D- Radioactive isotopes

Atoms of the same element that differ in atomic masses are called isotopes. Mainly, the heavier atoms with the higher atomic numbers will have the number of neutrons within the core more likely to exceed the number of protons. Isotopes of the same element are often found in nature alternately or in mixtures. For example, in Chlorine-17 some contain 18 neutrons and some contain 20 neutrons, meaning the mass numbers would be 35 and 37 so it'd be 35Cl ans 37Cl. In these isotopes, a great number are unstable and will fall apart during radioactive decay processes. An isotope will be radioactive if its nuclei are unstable. Large atomic nuclei are usually unstable, and therefore, more likely to be radioactive. Small atomic nuclei can also be radioactive if the ratio of neutrons to protons exceeds certain limits.