Rutherfordium (Rf)
Transition metal · Radioactive · Synthetic
Rutherfordium is the first “superheavy” transactinide element. Chemistry experiments with just a handful of atoms show it behaves like a heavier cousin of hafnium, exactly as the periodic table predicts.
Position on the periodic table
Atomic properties
| Atomic number | 104 |
|---|---|
| Atomic mass | 267 amu |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d2 |
| Noble gas shorthand | [Rn] 5f14 6d2 7s2 |
| Electrons per shell | 2, 8, 18, 32, 32, 10, 2 |
| Valence electrons (outer shell) | 2 |
| Common oxidation states | +4 |
| Electronegativity (Pauling) | Not available |
| Covalent radius (approx.) | Not available |
| First ionization energy | 580 kJ/mol |
| Electron affinity | Not available |
Physical properties
| State at 25 °C | Solid |
|---|---|
| Density | 23.2 g/cm³ |
| Melting point | 2126.8 °C (2400 K) |
| Boiling point | 5526.9 °C (5800 K) |
| Appearance | Not available |
| Radioactive | Yes |
| Origin | Synthetic (lab-made) |
Electron configuration of rutherfordium
Rutherfordium's ground-state electron configuration is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d2, usually shortened to [Rn] 5f14 6d2 7s2. Its electrons occupy 7 shells (2, 8, 18, 32, 32, 10, 2), placing it in period 7 of the d-block. Explore it interactively in the electron configuration calculator.
Uses of rutherfordium
- Fundamental research only
Biological role: None.
Occurrence: Entirely synthetic.
History and discovery
Discovered: 1964 — Joint Institute for Nuclear Research. Name origin: Named after Ernest Rutherford, pioneer of nuclear physics.
Claimed by Dubna (1964) and Berkeley (1969); the Cold War naming dispute was settled by IUPAC in 1997.
Safety notes
Radioactive; exists for seconds to minutes.
Educational context only — always follow your school's laboratory rules and never handle chemicals without proper supervision. See our disclaimer.
Practice questions
Quick practice: Rutherfordium
1. What is the chemical symbol of Rutherfordium?
2. What is the atomic number of Rutherfordium?
3. Which category does Rutherfordium belong to?
4. What is the state of Rutherfordium at room temperature?
5. Which period of the periodic table is Rutherfordium in?
Rutherfordium FAQs
What is the atomic number of rutherfordium?
Rutherfordium's atomic number is 104 — every rutherfordium atom has 104 protons in its nucleus.
What is the symbol for rutherfordium?
Rf. Named after Ernest Rutherford, pioneer of nuclear physics.
Is rutherfordium a metal, nonmetal, or metalloid?
Rutherfordium is classified as a transition metal.
What state is rutherfordium at room temperature?
At about 25 °C, rutherfordium is a solid. It melts at 2126.8 °C.
What is rutherfordium used for?
Key uses include: fundamental research only.
Related elements
Keep working with this element
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