why is the distribution of Isotopes not the equilibrium distribution, e.g, why do we still have hydrogen, helium, and uranium? ?
- Anonymous2 months ago
The reason elements are not distributed equally and the isotopes of those elements is that different amounts of energy are required to turn energy into matter. The Universe had to expand and cool down enough for energy to start converting to hydrogen, helium, a much smaller amount of lithium and an even smaller amount of beryllium. The Universe still has primordial hydrogen and helium. It takes less energy to to fuse 2 hydrogen protons into 2 helium protons and 1or 22 neutrons than it takes to create a lithium 6 or 7 nucleus. All of the other elements from nitrogen, carbon and oxygen through uranium and beyond are created in the cores of stars by various types of fusion processrs that require high pressures and temperatures. Those elements and isotopes get released to be recycled when a massive stars went hypernova or supernova and small mass stars have helium flashes and blow off their conductive and convective layers while the core of the low mass star collapses to become a white dwarf star.
Mass and energy are conserved, but it takes a lot of energy and more and more more energy to create more massive atomic nuclei.
Uranium 238 and 235 have long half lives, but they eventually become stable isotopes of lead.