Nihonium: Discovery, Properties, Uses and Isotopes

Content Curator

Nihonium is a super heavy p-block element, first synthesized by Japanese scientists in 2004. It is known to be one of the most expensive elements. Nihonium is a post-transition element of group 13 in the periodic table. As a synthetic element, Nihonium was known as Ununtrium(Uut). But it has changed now to Nihonium. It has an atomic number of 113 and an atomic mass of 286.

Table of Content

What is Nihonium?
Discovery of Nihonium
IUPAC Naming of Nihonium
Chemical Properties of Nihonium
Physical Properties of Nihonium
Isotopes of Nihonium
Uses of Nihonium
Things to Remember
Sample Questions

Read More: Thermochemistry

What is Nihonium?

Nihonium is a post-transition element of group 13 in the periodic table. As a synthetic element, Nihonium was known as Ununtrium(Uut). But it has been renamed as Nihonium. It has an atomic number of 113 & an atomic mass of 286. Nihonium is made up of 113 electrons, protons & 173 neutrons in its structure. The symbol of Nihonium is Nh.

Nihonium

Read More:

Group 15 elements	Dinitrogen	Oxides of Nitrogen

Discovery of Nihonium

In 1998, the first attempt was made by the JINR-LLNL collaboration on flerovium (atomic number-114). It was done by reacting plutonium-244 with ions of Ca 48. Ca 48 is considered an ideal projectile because it is a light element with high neutrons.

In 2004, there came the main experiment by Japanese scientists of Riken. They conducted a cold fusion of Bismuth(Bi⁸³ 209) with zinc (Zn³⁰ 70) and after waiting for nearly 10 months, they successfully synthesized an atom of Nihonium.

IUPAC Naming of Nihonium

According to IUPAC(International Union of Pure & Applied Chemistry), Nihonium or the metal in 113 was previously known as Ununtrium(Uu_t) [Un₁, tri₃]

Ununtrium

But after the discovery of element 113, IUPAC approved to name the atom after japan for their major contribution of synthesizing it. Japanese scientists proposed the name to be Nihonium from the word “Nihon” or ‘the land of the sun’.

Also, according to the Mendeleev nomenclature of the periodic table, another name of Nihonium would be eka-thallium.

Read More:

Nitric Acid	Phosphine	Oxoacids of Phosphorus

Chemical Properties of Nihonium

Nihonium is an element of group 13 and period 7.
Nihonium is an element of the Boron group.
Nihonium can be synthesized in 3 oxidation states: +1 & +3, +5. It has the most stability in the +3 state.
The boiling point, the melting point of Nihonium is yet to be found. They are unknown but assumed to be higher than previous members of its group.

Nihonium in Periodic Table

The density of nihonium is also unknown.
Nihonium is a post-transition metal. It is also called a transactinide element.
Compound elements with inert gases like-NhF₃ & NhCl₃ have the T-shape and NhBr₃ and NhI₃ of a trigonal plane in shape.
At a normal temperature of 25 degrees centigrade, Nihonium is solid.
Most stable Nihonium has a half-life of 20 seconds or so.
Nihonium is greater in size than thallium.

Read More: Noble gases

Physical Properties

Nihonium is the heaviest (super-heavy) element of group-13 of block 7p.
Nihonium is a metal, unlike Boron.
Nihonium has the spin-orbit interaction of 7p-shell for having electrons with high velocity inside its structure. So, it is quite different from the other elements of that group.
Valence electrons of nihonium are in 7s & 7p-shell.

Nihonium Valence electrons

It has the highest ionisation energy among group-13 which is 7.306eV.
Nihonium has the crystal structure of a hexagonal close-pack.
Nihonium has the same atomic radius as thallium.
Nihonium has similar properties as the ‘island of stability’ theory suggests.

Isotopes of Nihonium

Nihonium has 8 different isotopes among which two of them (Nh-287 & Nh-290) are still unconfirmed.
The atomic masses of Nihonium isotopes are 278, 282-287 & 290.
The heaviest and stable isotope is Nh-286.
Isotopes of nihonium are also reactive and mostly unstable.

Read More:

Properties of Matter	Atoms and Molecules	Difference between Elements and Compounds

Uses of Nihonium

For having little-to-no half-life, Scientists haven’t found any usage of Nihonium. Therefore, Nihonium has no usage other than scientific research.

Read More: Ozone

Some Facts about Nihonium

Only 3 atoms of Nihonium have been produced till now.
It takes a minimum of 500 days to produce 1 atom of Nihonium.
Nihonium has high radioactivity. Therefore, it is a self-destructive element that catches fire.
Nihonium is the first atomic element founded in Asia.
It is the most expensive atomic element ever.

Things to Remember

Nihonium is a highly radioactive chemical element.
According to the Mendeleev nomenclature of the periodic table, another name of Nihonium would be eka-thallium.
The most stable Nihonium(Nh-286) has only 20 sec of half-life.
The first element is found in Asia.
Most of Nihonium’s properties are unknown & predicted as of now.
Nihonium is one of the superheavy elements according to the ‘island of stability’ theory.

Read More:

Group 16 elements	Dioxygen	Sulphur dioxide

Sample Questions

Ques. Why does Nihonium have a very little half-life? (2 marks)

Ans: The stability of nuclei of an atomic element decreases when the atomic number increases. This happens due to the repulsion between protons. Therefore, the nucleus couldn’t be bound with strong nuclear forces. This instability creates spontaneous fission inside the atom of Nihonium. Hence, Nihonium has a very little half-life.

Ques. Why could Nihonium have the name ‘Eka-thallium’ according to the Mendeleev nomenclature? (2 marks)

Ans: The Mendeleev nomenclature gives priority to atomic masses for placing them in the periodic table. So, the spaces where elements were yet to be discovered, he predicted their name with the prefix ‘Eka’. Nihonium is placed after thallium in the table. So, It could be named ‘Eka-thallium’.

Ques. Why is Nihonium considered a post-transition metal? (2 marks)

Ans: Nihonium is considered a post-transition metal because

i) It is solid in nature at room temperature.

ii) It has a high density.

iii) It has been predicted that Nihonium has high boiling & melting points.

iv)It shows different oxidation states such as-+1,+3,+5.

Ques. Inert pair effect on Group-13 elements? (2 marks)

Ans: In the boron family, the common group oxidation state +3 is stable for lighter elements in the group. But as the elements get heavier, the inert pair effect increases & the oxidation state +1 becomes more stable for the elements.

Though the inert pair effect may vary sometimes, thallium +1 is the most stable ionised state(Tl⁺).

Read More:

Oxoacids of Sulphur	Hydrogen chloride	Interhalogen compounds

Ques. Explain what happens when Boric acid is heated. (2 marks)

Ans: Boric acid reacts when it is heated at a high temperature of more than 370 degrees centigrade. As a product of the reaction, it forms HBo₂ (metaboric acid). On further heating, the metaboric acid converts into boric oxide (B₂O₃).

Ques. Why is Boron used in nuclear reactions? Why do Boron halides form an additional compound with NH₃? (2 marks)

Ans: Boron is a good neutron absorber. Therefore, while the process of nuclear reaction happens, Boron can help to minimize the activation energy of the reaction by absorbing neutrons.

Boron halide is an electron-deficient compound. It has an oxidation state of +3 where 3 halides form a trivalent compound. So, it works as a lewis acid. On the other hand, NH₃, being a good electron-rich compound, forms a bond with its lone pair of electrons, which results in an additional compound with Boron halide.

Ques. Why does NH₃ form an H-bond but PH₃ doesn’t? (2 marks)

Ans: N₂ is highly electronegative than phosphorus. Nitrogen is also smaller in size. So, there is a greater electron attraction towards nitrogen in NH₃. Phosphorus is also greater in size and less electronegative. Therefore, NH₃ forms an H-bond.

Read More:

Group 18 elements	Coordination Compounds	Werner’s theory of coordination compounds

Ques. Why do Noble gases have very low boiling points? (2 marks)

Ans: Noble gases have a very low boiling point because they are monoatomic. With no such interatomic forces, they get liquefied at very low temperatures. And the weak dispersion forces in noble gas’ atoms are not strong enough.

Ques. Why is H₂S less acidic than H₂Te? (2 marks)

Ans: Due to the decrease in bond (E–H) dissociation enthalpy down the group, acidic character increases. As Te is further down in the group of periodic tables than S H₂S is less acidic than H₂Te

Ques. Discuss the molecular shape of BrF₃ on the basis of VSEPR theory? (2 marks)

Ans: The central atom Br has 7e^- in the valence shell. 3 of these will form electron-pair bonds with three fluorine atoms. Thus, there are 3 bond pairs and 2 lone pairs of 4e^-. According to VSEPR theory, these will occupy the corners of a trigonal bipyramid. The two lone pairs will occupy the equatorial positions to minimise lone pair-lone pair and the bond pair lone pair repulsions which are greater than the bond pair-bond pair repulsions. In addition, the axial fluorine atoms will be bent towards the equatorial fluorine in order to minimise the lone-pair-lone pair repulsions. The shape would be that of a slightly bent ‘T’.

Also Read: