Rhenium (Re)

Rhenium properties

Atomic number

75

Atomic mass

186.21 u

Category

Transition metal

Group

7

Period

6

Block

d-block

State at room temp.

Solid

Electronegativity

1.9

Melting point

3,459 K (3,185.8 °C)

Boiling point

5,869 K (5,595.8 °C)

Density

21.02 g/cm³

Valence electrons

2

Common charges

+4, +6, +7

Oxidation states

+7, +6, +4

Atomic radius

217 pm

Ionization energy

7.88 eV

Electron affinity

0.15 eV

Radioactive

No, has stable isotopes

Discovered

1925

Rhenium electron configuration

The electron configuration of Rhenium (Re) is [Xe] 4f14 5d5 6s2. Its 75 electrons are arranged in shells as 2, 8, 18, 32, 13, 2.

Protons, neutrons and electrons in Rhenium

A neutral Rhenium atom has 75 protons and 75 electrons. Most Rhenium atoms have about 111 neutrons: the atomic mass rounded to 186, minus the atomic number 75.

Neutrons are approximate: atoms of the same element can have different numbers of neutrons (isotopes). Atomic number and mass

How many valence electrons does Rhenium have?

2

Rhenium has 2 valence electrons, counting the electrons in its outermost s subshell. Like most transition metals, it can also use d electrons in bonding.

See every element: Periodic table with valence electrons

Rhenium orbital diagram

Each box is an orbital that holds up to two electrons with opposite spins (↑↓). The inner shells are the same as the noble gas in brackets. How to write electron configurations

Molar mass of Rhenium

186.21 g/mol

One mole of Rhenium atoms (6.022 × 10²³ atoms) has a mass of 186.21 grams. Use this value to convert between grams and moles.

Rhenium facts

• Rhenium was the last element with a stable isotope to be discovered.
• Rhenium melts at about 3,186 °C, a higher melting point than any other metal except tungsten.
• Rhenium (Re) has atomic number 75 and is a solid at room temperature. It was discovered in 1925.

Position in the periodic table

Rhenium is element 75, in period 6 and group 7 of the periodic table, in the d-block.

All transition metals

Uses of Rhenium

Rhenium is used mostly in nickel-based superalloys for the turbine blades of jet engines, where it helps the metal resist slowly deforming at very high temperatures. Platinum–rhenium catalysts are used in oil refineries to produce high-octane gasoline. Rhenium is also used in high-temperature thermocouples, electrical contacts, and the filaments of mass spectrometers.

Who discovered Rhenium?

German chemists Walter Noddack, Ida Tacke (later Ida Noddack), and Otto Berg discovered rhenium in 1925, detecting it with X-ray spectroscopy in platinum ore and the mineral columbite. They named it after the Rhine River, Rhenus in Latin.

Where does the name come from?

Rhenium comes from Rhenus, the Latin name for the Rhine River. German chemists Walter Noddack, Ida Tacke and Otto Berg discovered it in 1925 and named it after this river in their homeland.

Discovery timeline