Fluorine is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. As the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.
Owing to the expense of refining pure fluorine, most commercial applications use fluorine compounds, with about half of mined fluorite used in steelmaking.
Fluorine is obtained by the electrolysis of a solution of potassium hydrogendifluoride in anhydrous hydrofluoric acid.
Protons and Neutrons in Fluorine
Fluorine is a chemical element with atomic number 9 which means there are 9 protons in its nucleus. Total number of protons in the nucleus is called the atomic number of the atom and is given the symbol Z. The total electrical charge of the nucleus is therefore +Ze, where e (elementary charge) equals to 1,602 x 10-19 coulombs.
The total number of neutrons in the nucleus of an atom is called the neutron number of the atom and is given the symbol N. Neutron number plus atomic number equals atomic mass number: N+Z=A. The difference between the neutron number and the atomic number is known as the neutron excess: D = N – Z = A – 2Z.
For stable elements, there is usually a variety of stable isotopes. Isotopes are nuclides that have the same atomic number and are therefore the same element, but differ in the number of neutrons. Mass numbers of typical isotopes of Fluorine are 19.
Main Isotopes of Fluorine
Only one isotope of fluorine occurs naturally in abundance, the stable isotope 19F. The isotopes 17F and 18F undergo β+ decay and electron capture, lighter isotopes decay by proton emission, and those heavier than 19F undergo β− decay (the heaviest ones with delayed neutron emission).
Fluorine-19 is composed of 9 protons, 10 neutrons, and 9 electrons. Its abundance is 100%; no other isotopes of fluorine exist in significant quantities.
Fluorine-18 is composed of 9 protons, 9 neutrons, and 9 electrons. Of the unstable nuclides of fluorine, 18F has the longest half-life, 109.739 minutes. It has two decay modes, of which the main one is positron emission. For this reason 18F is a commercially important source of positrons.
Fluorine-20 is composed of 9 protons, 11 neutrons, and 9 electrons. Fluorine-20 is one of the more unstable isotopes of fluorine. It has a half-life of 11.07 seconds and undergoes beta decay.
Electrons and Electron Configuration
The number of electrons in an electrically-neutral atom is the same as the number of protons in the nucleus. Therefore, the number of electrons in neutral atom of Fluorine is 9. Each electron is influenced by the electric fields produced by the positive nuclear charge and the other (Z – 1) negative electrons in the atom.
Since the number of electrons and their arrangement are responsible for the chemical behavior of atoms, the atomic number identifies the various chemical elements. The configuration of these electrons follows from the principles of quantum mechanics. The number of electrons in each element’s electron shells, particularly the outermost valence shell, is the primary factor in determining its chemical bonding behavior. In the periodic table, the elements are listed in order of increasing atomic number Z.
Electron configuration of Fluorine is [He] 2s2 2p5.
Possible oxidation states are -1.
Fluorine forms a great variety of chemical compounds, within which it always adopts an oxidation state of −1. With other atoms, fluorine forms either polar covalent bonds or ionic bonds. Most frequently, covalent bonds involving fluorine atoms are single bonds, although at least two examples of a higher order bond exist. Fluorine’s chemistry includes inorganic compounds formed with hydrogen, metals, nonmetals, and even noble gases; as well as a diverse set of organic compounds.
Typical Chemical Compound of Fluorine
Uranium conversion is one of processes of nuclear fuel cycles, in which uranium is chemically purified and converted into the chemical form of uranium hexafluoride (UF6), the input stock for most commercial uranium enrichment facilities. Uranium hexafluoride, known also as “hex”, is a chemical compound used in the process of enriching uranium, which produces fuel for nuclear reactors. At atmospheric pressure, uranium hexafluoride sublimes at 56.5 °C. At this stage of the cycle the uranium hexafluoride conversion product still has the natural isotopic mix, i.e. it contains only 0.71% of fissile isotope 235U.
|Number of protons||9|
|Number of neutrons (typical isotopes)||19|
|Number of electrons||9|
|Electron configuration||[He] 2s2 2p5|
Properties of other elements