Which of the isotopes are radioactive? Check all that apply. hydrogen-1 hydrogen-3 helium-4 carbon-14 uranium-235 copernicium-277 fermium-252 carbon-12

As the unstable nucleus changes, it gives off radiation and is said to be radioactive. Radioactive isotopes are often called radioisotopes. All elements with atomic numbers greater than 83 are radioisotopes meaning that these elements have unstable nuclei and are radioactive.

Explanation:

answer; protein;

the answer for sodium is 0.186

the answer for rubidium is 0.251