Rutherfordium (symbol Rf, atomic number 104) is the first transactinide, a synthetic superheavy transition metal. It is classified as a transition metal and sits in group 4, period 7 of the periodic table.
Overview
Rutherfordium is the chemical element with atomic number 104 and the symbol Rf. With a standard atomic weight of [267], it is a transition metal. In the periodic table it occupies group 4 and period 7, and under standard conditions it is normally a solid. Rutherfordium is the first transactinide, a synthetic superheavy transition metal.
Atomic structure
An atom of Rutherfordium has 104 protons in its nucleus and, when neutral, 104 electrons arranged in the configuration [Rn] 5f14 6d2 7s2. Rutherfordium has no stable isotope; the value [267] refers to the mass number of its most stable or most commonly produced isotope.
Discovery and place in the table
Rutherfordium was discovered in 1964 by Joint Institute for Nuclear Research. It follows Lawrencium (Lr) and precedes Dubnium (Db) in order of atomic number.
| Atomic number | 104 |
|---|---|
| Symbol | Rf |
| Atomic mass | [267] |
| Category | Transition metal |
| Group | 4 |
| Period | 7 |
| Electron configuration | [Rn] 5f14 6d2 7s2 |
| Phase at STP | Solid |
| Discovered | 1964 (Joint Institute for Nuclear Research) |