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Fermium

What is Fermium

Fermium (pronounced as FER-mee-em) [2] is a synthetic, transuranium, radioactive element [3] with the symbol Fm [1] belonging to the family of inner transition metals [10]. It has 18 isotopes with mass numbers ranging from 242 to 259 of which Fm-257 is the most stable isotope with a half-life of 100.5 days [2, 3]. It decays into californium-253 through alpha emission and spontaneous fission [2].

Fermium Symbol

Where Is it Found

It cannot be found naturally on earth [3]. However, it can be obtained in microgram quantities by the neutron bombardment of plutonium in a nuclear reactor [1].

History of the Element

Origin of the Name: The element is named after the famous nuclear physicist Enrico Fermi [1].

Who Discovered it: It was discovered by a team of scientists led by Albert Ghiorso on October 31, 1952 [2, 3].

How was it Discovered

The first isotope of fermium (later named as fermium-255), was found in the nuclear debris after the thermonuclear explosion of the first hydrogen bomb (codenamed Ivy Mike [3, 10]) on an atoll in the Pacific Ocean [1]. It was because uranium-238, the source of heat for the detonation, was exposed to a flux of neutrons during the process and combined with 17 of them to produce Fm-255 that has a half-life of about 20 hours [1, 2].

It was later produced in the laboratory by a group at the Nobel Institute of Stockholm. They bombarded uranium-238 with oxygen nuclei producing fermium-250 with a half-life of 30 minutes [1].

Fermium Identification

Atomic Number 100 [2]
CAS Number  7440-72-4 [1]
Position in the periodic table Group: Actinides[1] Period: 7 [1] Block: f [1]

Location of Fermium in the Periodic Table

Properties and Characteristics of Fermium

General Properties

Atomic mass 257 atomic mass units [8,9]
Mass number 257 [5]

Physical Properties

Color/appearance Unknown [3,7]
Luster Unknown [16]
Texture Unknown [14]
Melting point/freezing point 1527°C (2781°F) [1]
Boiling point Unknown [1]
Density Unknown [1]
State of matter at room temperature (natural state) Solid [1,2]
Hardness Unknown [12, 15]

Chemical Properties

Flammability Unknown
Oxidation state/Oxidation number +2, +3 [1]
Reactivity Unknown [13]

Atomic Data of Fermium (Element 100)

Valence electrons 2 [4]
Quantum numbers
–          n 5 [4]
–          ℓ 3 [4]
       –      m 1 [4]
       –      m s [4]
Electron configuration (noble gas configuration) [Rn]5f127s2 [3]
Atomic structure
–          Number of Electrons 100 [3]
–          Number of Neutrons 157 [3]
–          Number of Protons 100 [3]
Energy levels
–          First Energy Level 2 [3]
–          Second Energy Level 8 [3]
–          Third Energy Level 18 [3]
–          Fourth Energy Level 32 [3]
–          Fifth Energy Level 30 [3]
–          Sixth Energy Level 8 [3]
–          Seventh Energy Level 2 [3]
Radius of atom
       –       Atomic Radius 2.45 Å [1]
       –       Covalent Radius 1.67 Å [1]
Electronegativity 1.3 [6]
Ionization energy

(kJmol-1) [1]

1st 2nd 3rd 4th 5th 6th 7th
627.2

Fermium Electronic Configuration (Bohr Model)

Uses of Fermium

Due to its minute production and short half-life, it is used for research purposes only [2].

Health Hazards

It is potentially dangerous due to its radioactivity [1].

Interesting Facts

  • Fermium, along with Einsteinium, was one of the first synthetic elements produced after the testing of a hydrogen bomb [10, 15].
  • As the hydrogen bomb testing was top secret, researchers could only publish the discovery of Fm in 1955 after producing it officially in a laboratory [1, 3, 10].

Cost of Fermium

Unavailable since it is not found naturally and only produced in nuclear reactors [3].

    References

  1. http://www.rsc.org/periodic-table/element/100/fermium
  2. https://education.jlab.org/itselemental/ele100.html
  3. https://www.chemicool.com/elements/fermium.html
  4. http://chemistry-reference.com/q_elements.asp?Symbol=Fm&language=en
  5. Pubchem.ncbi.nlm.nih.gov
  6. https://www.nuclear-power.net/fermium-affinity-electronegativity-ionization/
  7. http://www.elementalmatter.info/element-fermium.htm
  8. http://www.chemicalelements.com/elements/fm.html
  9. http://hobart.k12.in.us/ksms/PeriodicTable/fermium.htm
  10. https://study.com/academy/lesson/fermium-element-properties-uses-facts.html
  11. Lenntech.com
  12. http://periodictable.com/Elements/100/data.html
  13. https://www.webelements.com/fermium/chemistry.html
  14. http://www.answers.com/Q/What_is_the_texture_of_fermium
  15. https://www.schoolmykids.com/learn/interactive-periodic-table/Fm-Fermium/
  16. http://www.answers.com/Q/Is_the_element_fermium_luster
  17. http://large.stanford.edu/courses/2015/ph241/singh-a1/

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