Vanadium is a hard, silvery grey, ductile, and malleable transition metal. Vanadium is mainly used to produce specialty steel alloys such as high-speed tool steels, and some aluminium alloys. Vanadium is generally added to steel to inhibit grain growth during heat treatment. Vanadium occurs naturally in about 65 minerals and in fossil fuel deposits. It is produced in China and Russia from steel smelter slag.
Protons and Neutrons in Vanadium
Vanadium is a chemical element with atomic number 23 which means there are 23 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 Vanadium are 51.
Main Isotopes of Vanadium
Naturally occurring vanadium is composed of one stable isotope, 51V, and one radioactive isotope, 50V. The latter has a half-life of 1.5×1017 years and a natural abundance of 0.25%.
Vanadium-50 is composed of 23 protons, 27 neutrons, and 23 electrons.
Vanadium-51 is composed of 23 protons, 28 neutrons, and 23 electrons. 51V has a nuclear spin of 7⁄2, which is useful for NMR spectroscopy.
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 Vanadium is 23. 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 Vanadium is [Ar] 3d3 4s2.
Possible oxidation states are +2,3,4,5.
The chemistry of vanadium is noteworthy for the accessibility of the four adjacent oxidation states 2–5. Vanadium(II) compounds are reducing agents, and vanadium(V) compounds are oxidizing agents. Vanadium(IV) compounds often exist as vanadyl derivatives, which contain the VO2+ center.
Most Common Alloy of Vanadium
High-speed steels are complex iron-base alloys of carbon, chromium, vanadium, molybdenum, or tungsten, or combinations there of. Vanadium is generally added to steel to inhibit grain growth during heat treatment. In controlling grain growth, it improves both the strength and toughness of hardened and tempered steels. The size of the grain determines the properties of the metal. For example, smaller grain size increases tensile strength and tends to increase ductility. A larger grain size is preferred for improved high-temperature creep properties. Vanadium is added to promote abrasion resistance and to produce hard and stable carbides which being only partly soluble, release little carbon into the matrix.
|Number of protons
|Number of neutrons (typical isotopes)
|Number of electrons
|[Ar] 3d3 4s2