No, the stability of elements peaks at iron and nickel and declines again after that. If you look at the curve of binding energy per nucleon [1], the trend is q

No, the stability of elements peaks at iron and nickel and declines again after that. If you look at the curve of binding energy per nucleon [1], the trend is quite obvious. Note in particular that at some point past uranium, the average binding energy declines to below that of helium, making the isotopes extremely susceptible to alpha particle emission. There are some "islands of relative stability", where heavy elements are stabilized by "magic numbers" of protons and neutrons -- which is why thorium and uranium are so long lived. But we can be quite certain that there is no such thing as Element 200. [1] https://en.wikipedia.org/wiki/File:Binding_energy_curve_-_common_isotopes.svg https://en.wikipedia.org/wiki/File:Binding_energy_curve_-_co...