Fermium Properties (25 Facts You Should Know)

Fermium properties can be identified to emerge knowledge about the periodic element Fermium. Let us define the Fermium properties in an exhaustive manner below.

Fermium properties refer to the internal and external features held by Fermium, which have been discovered as soon as the element was discovered first. The chemical and physical properties are notion of identifying or differentiating this element from a large number in periodic element.

The properties of Fermium are needed to be studied for knowing the existence of Fermium in the periodic table. The special features of the element would also be identified through this article. Properties such as melting point, boiling point, electronegativity others would be discussed throughout the article.

Fermium symbol

The symbol of Fermium is Fm. The first letter ‘F’ and the most emphasised letter ‘m’ from “Fermium” are used together as the short form of the name and its symbol.

Fermium group in periodic table

No specific group division has been done for Fermium due to its multiple characteristics.

Fermium period in periodic table

Fermium is placed at period 7 with other aktinied elemente.

Fermium block in periodic table

Fermium can be identified in f blok of the period table as it has filled f orbital in a structure of a single atom.

Fermium atomic number

Atomic number of Fermium is 100. It has 100 protons with positive charge at the centre and 100 electrons with negative charge in outer shells keeping the neutrality inside the atom.

fermium properties
Atomic number of Fermium

Fermium atomic Weight

The atomic weight of Fermium is 257 u; here atomic weight is the relative term of atomic mass.

Fermium Electronegativity according to Pauling

The electronegativity of Fermium has been measured in Pauling scale as 1.3, which is same as the electronegativity of Einsteinium, Berkelium, Thorium, Americium, Curium, californium and many other elements in the table.

Fermium atomic Density

The predicted amount of atomic density of Fermium is 9.7(1) g/cm3 at STP measure.

Fermium melting point

The melting point of Fermium can be predicted by chemists as 1527 °C (1800 K, 2781 °F).

Fermium boiling point

The boiling point of Fermium cannot be measured yet due to its highly reactive nature and heavy appearance.

Fermium Van der Waals radius

Die Van der Waal se radius of Fermium is still undefined as this is one of the largest actinides in the series.

Fermium ionic/covalent radius

The covalent radius of Fermium is also unknown until this day as there no evidence exists for the formation of covalent bond by Fermium in chemistry.

Fermium isotopes

Isotopes are the different forms of an atom with different number of nucleons and same number of protons. Let us identify the isotopes of Fermium below.

Four isotopes of Fermium has been discovered, those are 252Fm, 253Fm, 255Fm, 257Fm. 255 Fm is the most unstable isotope and 257Fm is the most stable isotope of the element. The half lives of the isotopes are mentioned in the table below.

252Fm25 uur
253Fm3 dae
255Fm20 uur
257Fm100 dae
Isotopes of Fermium and their half-life

Fermium electronic shell

Electron shells are those pathways around the nucleons of an atom where the electrons are arranged in specific manner. Let us signify the fact about electronic shell of Fm here.

The number of electronic shell in an atom of Fermium is 7. The electronic arrangement in that shell can be obtained as 2, 8, 18, 32, 30, 8, and 2.

Fermium energy of first ionisation

Die eerste ionisasie energie for leaving first valence electron required by Fermium is 629 kJ/mol.

Fermium oxidation states

It has been identified that +2 and +3 oxidation states are displayed by Fermium. It means the element can reduce highest 3 electrons from its valence shell.

Fermium electron configurations

Electron configuration refers to the representation of electron arrangement within an atom of a specific element. let us identify the structure of electron arrangement in Fermium below.

The electronic configuration of Fermium element is [Rn] 5f12 7s2.  It has been arranged in this way as per the rule of Aufbau principle and Redon is the ideal noble gas for the Fm.

Fermium CAS number

The CAS registration number given to Fermium is 7440-72-4 for identifying the element in Chemical Abstract Service.

Fermium ChemSpider ID

In ChemSpider database Fermium has been given 22434-identity number for getting free access on the data and information of the element.

Fermium allotropic forms

Allotropic forms are defined as the forms of a specific atom where differ by the structural format and some physical properties. Let us find if Fm has allotropic forms or not.

Fermium has no allotropic forms. It is predicted that the element appears in a natural form with a structural figure of face-centred cubic structure.

Fermium chemical classification

  • Fermium can be chemically classified by its synthetic appearance.
  • Fermium is the heaviest actinide in the series and the element is chemically much reactive than other elements.
  • Fermium is very unstable in nature due to it’s formation from neutron bombardment.

Fermium state at room temperature

Fermium can be found in solid state at room temperature.

Is Fermium paramagnetic?

Paramagnetic elements are found to possess a single unpaired electron in any of its orbitals. Let us signify the magnetic effect imposed by Fermium in this section.

The magnetic appearance of Fermium has not been recognised yet due to its shorter life span.


Fermium has been identified to impose a unique appearance in the periodic table by its different characteristics. This element is quite similar with other actinide elements so it is placed in the actinide series just after Einsteinium.

Sarnali Mukherjee

Hi.....ek is Sarnali Mukherjee, 'n gegradueerde van die Universiteit van Calcutta. Ek hou daarvan om te onderrig en kennis oor chemie te deel. Ek het sedert 'n jaar gelede geleidelik belangstelling in artikelskryf gekry. Ek sal graag in die toekoms meer kennis oor my onderwerp wil opdoen. Kom ons koppel deur LinkedIn: https://www.linkedin.com/in/sarnali-mukherjee-921b59231

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