104Rf[267]
Rutherfordium (Rf)
Element 104 · Transition metal
Rutherfordium (Rf) is a chemical element with atomic number 104. It is classified as a transition metal in period 7, group 4 of the periodic table (the d-block). Its most stable known isotope has mass number 267 and its ground-state electron configuration is [Rn] 5f¹⁴ 6d² 7s². Its properties are largely predicted, as only a few atoms have ever been produced.
Rutherfordium facts
| Atomic number (Z) | 104 |
|---|---|
| Symbol | Rf |
| Mass number of most stable isotope | [267] |
| Category | Transition metal |
| Group | 4 |
| Period | 7 |
| Block | d-block |
| Electron configuration | [Rn] 5f¹⁴ 6d² 7s² |
| Electronegativity (Pauling) | — |
| State at 20 °C | Unknown (synthetic) |
| Protons / electrons | 104 / 104 |
| Neutrons (most common isotope, approx.) | 163 |
| Molar mass | 267 g/mol |