Scientists have discovered and synthesized an entirely new isotope of the highly radioactive element uranium. But it might last only 40 minutes before decaying into other elements.
The new isotope, uranium-241, has 92 protons (as all uranium isotopes do) and 149 neutrons, making it the first new neutron-rich isotope of uranium discovered since 1979. While atoms of a given element always have the same number of protons, different isotopes, or versions, of those elements may hold different numbers of neutrons in their nuclei. To be considered neutron-rich, an isotope must contain more neutrons than is common to that element.
