Symbol	Re
Atomic number	75
Group	7 (Manganese group)
Period	6
Block	d
Classification	Transition Metal

Appearance	Silvery-grayish
Color	Gray

Number of protons	75 p+
Number of neutrons	111 n0
Number of electrons	75 e-

From Wikipedia, the free encyclopediaRhenium is a chemical element with symbol Re and atomic number 75. It is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an estimated average concentration of 1 part per billion (ppb), rhenium is one of the rarest elements in the Earth's crust.

Phase at STP	Solid
Density	21.02 g/cm3
Atomic weight	186.207 u

Melting point	3459 K 3185.85 °C 5766.53 °F
Boiling point	5869 K 5595.85 °C 10104.53 °F
Heat of vaporization	707.1 kJ/mol

Electronegativity (Pauling Scale)	1.9
Electron affinity	5.8273 kJ/mol
Oxidation states	−3, −1, 0, +1, +2, +3, +4, +5, +6, +7 (a mildly acidic oxide)
Ionization energies	760 kJ/mol 1260 kJ/mol 2510 kJ/mol 3640 kJ/mol

Electron configuration Shorthand configuration	[Xe] 4f14 5d5 6s2
Electron configuration Full configuration	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d5 6s2
Electron configuration chart	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d5 6s2
Electrons per shell	2, 8, 18, 32, 13, 2
Valence electrons	2
Valency electrons	7
Bohr model	Figure: Shell diagram of Rhenium (Re) atom.
Orbital Diagram 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 6s

Discovery	Walter Noddack, Ida Noddack, Otto Berg (1925)
First isolation	Walter Noddack, Ida Noddack (1928)
Discovery of rhenium In 1922, Walter Noddack and Ida Tacke (future spouses Noddack) began searching for the elements number 43 (technetium) and 75 (rhenium). The Noddacks extracted 1 mg of oxide of what they believed to be element number 75 from platinum ore, and by X-ray emission spectroscopy found lines belonging to element number 75. Then the Noddacks published the discovery of element number 75 and named it rhenium after the river Rhine in Europe.

CAS Number	7440-15-5
ChemSpider ID	22388
EC number	231-124-5
PubChem CID Number	23947