Rhenium is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table.
Protons and Neutrons in Rhenium
Rhenium is a chemical element with atomic number 75 which means there are 75 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 Rhenium are 185, 187.
Main Isotopes of Rhenium
Rhenium occurs in 2 natural isotopes: 185Re and 187Re. 187Re is very slightly radioactive, decaying by beta decay with a half-life of 4.12×1010 years but it still is the most common isotope, having a natural abundance of approximately 62%.
Rhenium-185 is composed of 75 protons, 110 neutrons, and 75 electrons.
Rhenium-187 is composed of 75 protons, 112 neutrons, and 75 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 Rhenium is 75. 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 Rhenium is [Xe] 4f14 5d5 6s2.
Possible oxidation states are +4,67.
Most Common Alloys of Rhenium
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||75|
|Number of neutrons (typical isotopes)||185, 187|
|Number of electrons||75|
|Electron configuration||[Xe] 4f14 5d5 6s2|
Properties of other elements