Edwin McMillan and Philip Abelson of the USA
Not necessary for life.
Named after the planet Neptune, neptunium is a silvery, radioactive metal that is chemically active, reacting with air, water and acids but not bases. It is found in minute quantities in uranium minerals and ores, but it must be created artificially in any significant quantity. Neptunium has few uses, one of which is in neutron detectors. The most stable isotope of neptunium has a half-life of 2,140,000 years.
Neptunium has no biological use.
Role in Life Processes
No known benefits for life processes in plants and animals.
Neptunium is obtained by particle bombardment of uranium.