These processes produce most of the chemical elements in the universe heavier than zirconium (element 40), because nuclear fusion processes become increasingly inefficient and unlikely for elements heavier than this. By convention, such heavier elements produced in normal elemental abundance, are not referred to as "nucleogenic".
These processes create most of the heavy chemical elements in the universe heavier than zirconium (element 40), because nuclear fusion becomes increasingly inefficient and unlikely for elements greater than this. By custom, such heavier elements produced in normal amounts are not termed "nucleogenic".