Are all nuclei the same size?

No, not all nuclei are the same size. The size of a nucleus varies depending on the element and its isotopes, with larger nuclei typically found in heavier elements. Generally, atomic nuclei are measured in femtometers (10^-15 meters), and their size is influenced by the number of protons and neutrons they contain. Additionally, nuclear size can also be affected by factors such as nuclear interactions and the specific arrangement of nucleons.