>>2339524There can be radioactive isotopes of any element, really. Just because the stable nucleus is most common in nature, does not mean that unstable ones cannot exist. You know how molar mass is a decimal number? That's because it's the AVERAGE molar mass of the element, meaning that there are plenty of isotopes with different numbers of neutrons in the nucleus. Many of those isotopes are unstable and undergo radioactive decay - Hence, why we can use the decay of radioactive potassium nuclei for dating rocks, even though most potassium is not radioactive.
TL,DR; You're a retard.
