Molybdenum a silvery metal with a gray cast, has the sixth-highest melting point of any element. It readily forms hard, stable carbides in alloys, and for this reason most of world production of the element (about 80%) is used in steel alloys, including high-strength alloys and superalloys.
Protons and Neutrons in Molybdenum
Molybdenum is a chemical element with atomic number 42 which means there are 42 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 Molybdenum are 94-98.
Main Isotopes of Molybdenum
Molybdenum occurs in 7 natural isotopes: 92Mo, 94Mo, 95Mo, 96Mo, 97Mo, 98Mo and 100Mo. Of these, 100Mo is very slightly radioactive, decaying by double beta decay with a half-life of 7.8×1018 years. 98Mo is the most common isotope, having a natural abundance of approximately 24%.
Molybdenum-92 is composed of 42 protons, 50 neutrons, and 42 electrons.
Molybdenum-94 is composed of 42 protons, 52 neutrons, and 42 electrons.
Molybdenum-95 is composed of 42 protons, 53 neutrons, and 42 electrons.
Molybdenum-96 is composed of 42 protons, 54 neutrons, and 42 electrons.
Molybdenum-97 is composed of 42 protons, 55 neutrons, and 42 electrons.
Molybdenum-98 is composed of 42 protons, 56 neutrons, and 42 electrons.
Molybdenum-100 is composed of 42 protons, 58 neutrons, and 42 electrons.
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 Molybdenum is 42. 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 Molybdenum is [Kr] 4d5 5s1.
Possible oxidation states are +6.
Most Common Alloys of Molybdenum
About 86% of molybdenum produced is used in metallurgy, with the rest used in chemical applications. The estimated global use is structural steel 35%, stainless steel 25%, chemicals 14%, tool & high-speed steels 9%, cast iron 6%, molybdenum elemental metal 6%, and superalloys 5%.
Mo-25 Re Alloy. Molybdenum and rhenium are both refractory metals. These metals are well known for their extraordinary resistance to heat and wear. Key requirements to withstand high temperatures are a high melting point and stable mechanical properties (e.g. high hardness) even at high temperatures. These metals are usually combined together to obtain desired fabricability, thermal and mechanical properties.
|Number of protons||42|
|Number of neutrons (typical isotopes)||94-98|
|Number of electrons||42|
|Electron configuration||[Kr] 4d5 5s1|
Properties of other elements