Synthetic element

Synthetic elements are chemical elements that do not occur naturally on Earth and have instead been created artificially through nuclear reactions. These elements—characterised by atomic numbers 95 to 118—are produced by bombarding atomic nuclei with high-energy particles in nuclear reactors, particle accelerators or nuclear explosions. Although a small number of elements first synthesised in laboratories were later found in trace natural quantities, the vast majority exist only because of human scientific intervention.

Nature and Production of Synthetic Elements

Elements heavier than plutonium (atomic number 94) decay too rapidly for any primordial atoms to remain on Earth today. Their presence is therefore entirely the result of deliberate nuclear experiments or the by-products of nuclear detonations and reactor processes. The method for synthesising such elements involves forcing additional protons into the nucleus of a lighter element, thus increasing its atomic number. These reactions may involve neutron absorption, alpha-particle bombardment or heavy-ion fusion.
All known superheavy elements are unstable. Their isotopes exhibit half-lives ranging from microseconds to millions of years. Because no natural isotopic abundance exists for these elements, the atomic mass listed in the periodic table refers to the mass number of the most stable known isotope, given in brackets.
A small set of elements—technetium, promethium, astatine, neptunium and plutonium—were first produced synthetically, but were subsequently identified in minute natural quantities. Owing to their scarcity, they are often grouped with the exclusively synthetic elements.

Physical and Chemical Properties

With atomic numbers greater than 94, synthetic elements undergo radioactive decay at a rate that makes their natural persistence impossible. Their instability arises from the large number of protons in their nuclei, which increases electrostatic repulsion and weakens nuclear binding forces. Researchers have predicted an island of stability at higher atomic numbers where certain isotopes may have comparatively longer half-lives, although such elements would still be unstable on geological timescales.
Only elements up to fermium (atomic number 100) have been produced in quantities sufficient for limited chemical study. Heavier elements are typically created atom by atom and identified by their decay signatures. No element with atomic number greater than 99 has any commercial application; all are used solely in scientific research.

Historical Development of Synthetic Elements

The synthesis of technetium in 1937 marked the first creation of an element absent from nature. Its discovery filled a long-standing gap in the periodic table. The absence of stable technetium isotopes explains why none has survived since Earth’s formation; only minute quantities are produced naturally today via uranium fission or neutron capture in molybdenum.
Plutonium, first synthesised in 1940, is notable as the heaviest element occurring naturally, albeit in exceedingly small quantities. It became well known for its role in nuclear weapons and reactors.
Curium, produced in 1944 by Glenn T. Seaborg, Ralph A. James and Albert Ghiorso through alpha-particle bombardment of plutonium, was the first element created entirely artificially. Subsequent years saw rapid progress in synthesising new transuranium elements:

• Americium, berkelium and californium followed curium in the mid-1940s.
• Einsteinium and fermium were identified in 1952 from the debris of the first hydrogen bomb test, marking a significant scientific milestone.
• Mendelevium, nobelium and lawrencium were synthesised soon afterwards.
• Rutherfordium and dubnium were produced independently by Soviet and American research teams during the Cold War, leading to prolonged disputes over naming rights—the “transfermium wars”.
• A series of German discoveries added bohrium, hassium, meitnerium, darmstadtium, roentgenium and copernicium to the periodic table.
• Nihonium (element 113) was first created in Japan, marking an important achievement in the field.
• The final known elements—flerovium, moscovium, livermorium, tennessine and oganesson—were produced in Russian–American collaborations and complete the seventh period of the periodic table.

List of Synthetic Elements

The recognised synthetic elements are those with atomic numbers 95 (americium) through 118 (oganesson). These elements do not occur naturally and must be produced artificially. Each is radioactive, with distinct decay chains and half-lives.
Elements with atomic numbers 1 through 94 do occur naturally, but a subset—technetium, promethium, astatine, neptunium and plutonium—are often included in discussions of synthetic elements because their discovery first occurred through laboratory synthesis before their natural presence was confirmed.

Scientific Importance

Synthetic elements are vital to the study of nuclear structure, the limits of the periodic table and the forces that stabilise atomic nuclei. Their creation provides evidence for theories of nuclear shells and helps guide research toward the predicted island of stability. Although they lack practical industrial uses, synthetic elements remain central to cutting-edge research in nuclear physics, radiochemistry and the design of next-generation particle accelerators.