Introduction to Nihonium
Nihonium (Nh) is a synthetic chemical element with atomic number 113. It is a superheavy element, meaning it does not occur naturally on Earth and can only be produced artificially in specialized laboratories. Its name originates from “Nihon,” one of the two Japanese words for Japan, recognizing the contributions of the RIKEN Nishina Center for Accelerator-Based Science in Japan, where it was discovered.
Physical and Chemical Properties
Nihonium is located in Group 13 of the periodic table, directly below Thallium (Tl). Based on its position, it is classified as a p-block transactinide element. Scientists predict that Nihonium would exhibit metallic properties and belong to the boron group, which includes elements like aluminium, gallium, and indium, commonly used in various industrial applications in countries like India.
Theoretical calculations suggest that Nihonium would likely exist in oxidation states of +1 and +3. Due to relativistic effects, which become increasingly significant for very heavy elements, the +1 oxidation state is expected to be more stable than the +3 oxidation state, similar to Thallium. However, due to its extremely short lifespan, these properties are theoretical, and no direct experimental chemical studies have been possible.
Reactivity with Water and Air
Given the incredibly short half-lives of its known isotopes (ranging from milliseconds to seconds), Nihonium atoms exist for such brief periods that macroscopic quantities cannot be accumulated. Consequently, its reactivity with common substances like water or air cannot be observed or measured experimentally. It decays almost instantaneously after formation. If it were stable, its metallic nature and position in Group 13 would suggest it could potentially react with air (forming an oxide) or water, but this remains entirely hypothetical due to its inherent instability.
Safety Profile: Toxicity, Radioactivity, and Flammability
All known isotopes of Nihonium are highly radioactive. This extreme radioactivity is its most defining characteristic and the primary hazard associated with the element. Nihonium nuclei rapidly undergo alpha decay or spontaneous fission, transforming into lighter elements.
The concept of toxicity for Nihonium is largely academic. While, like other heavy metals, it would theoretically be toxic if ingested or absorbed into the body in significant amounts, its extreme instability means that such exposure is impossible. The dominant concern would be the radiation emitted by its decaying atoms, not its chemical toxicity.
Nihonium is not considered flammable. Metals generally do not exhibit flammability in the way organic compounds do. Any potential reaction with oxygen would be an oxidation process, not combustion.
Notable Interactions or “Reactions”
It is important to clarify that no chemical reactions involving Nihonium have ever been observed or studied. The element’s fleeting existence prevents any classical chemical experimentation where atoms interact to form compounds through electron rearrangement.
The “reaction” most associated with Nihonium is its synthesis through nuclear fusion, a process where atomic nuclei combine. For instance, isotopes of Nihonium were initially created by bombarding a target of bismuth-209 ($^{209}$Bi) with accelerated zinc-70 ($^{70}$Zn) ions. This process results in the fusion of the nuclei, followed by the emission of neutrons, to produce a Nihonium isotope. A representative nuclear reaction used for its synthesis can be shown as:
$^{209}{83}\text{Bi} + ^{70}{30}\text{Zn} \rightarrow ^{278}_{113}\text{Nh} + 1\text{n}$
This equation illustrates a nuclear fusion event, where the bismuth and zinc nuclei combine to form a superheavy Nihonium nucleus, and a neutron is emitted. This is a nuclear process, not a chemical reaction involving the formation or breaking of chemical bonds.