Rhenium (Re)
Element 75 · Transition metal · Solid at 25 °C · Group 7, Period 6
Rhenium was one of the last stable elements to be discovered (1925). With one of the highest melting points known, it strengthens jet-engine superalloys.
On the periodic table, rhenium sits in group 7 in period 6. It is one of 38 elements classified as a transition metal, and at room temperature (25 °C) it is a solid.
Transition metals occupy the wide d-block in the middle of the table. As a family they are hard, dense, high-melting metals that conduct heat and electricity well. Their partly filled d-orbitals let many of them take several oxidation states, form vividly colored compounds, and act as catalysts — which is why so much of industry, and so much of biology, runs on this block.
Properties of rhenium
| Atomic number (Z) | 75 |
|---|---|
| Symbol | Re |
| Atomic mass | 186.21 |
| Category | Transition metal |
| Group | 7 |
| Period | 6 |
| Block | d-block |
| Metal / nonmetal | Metal |
| State at 25 °C | Solid |
| Electron configuration | [Xe] 4f14 5d5 6s2 |
| Electronegativity (Pauling) | 1.9 |
| Melting point | 3,186 °C (3,459.15 K / 5,766.8 °F) |
| Boiling point | 5,596 °C (5,869.15 K / 10,104.8 °F) |
| Density | 21.02 g/cm³ |
Position in the periodic table
Rhenium shares group 7 with Manganese (Mn), Technetium (Tc), Bohrium (Bh). Elements in the same group have the same number of outer electrons, so they tend to behave alike chemically — comparing them is one of the fastest ways to see periodic trends in action.
Within this dataset, it has the #4 highest measured density of the 97 elements with recorded values; its melting point is the #3 highest of the 102 elements with measured melting points.
Physical properties
Rhenium melts at 3,186 °C (3,459.15 K / 5,766.8 °F) and boils at 5,596 °C (5,869.15 K / 10,104.8 °F), giving it a liquid range of about 2,410 °C at standard pressure.
Its density is 21.02 g/cm³.
See also: the interactive periodic table, how to read the periodic table, periodic trends.