Rutherfordium is a radioactive research element beyond the actinides. Accelerator reactions involving californium and carbon nuclei have produced its isotopes. Its identification connects nuclear synthesis with the periodic table, where the group assignment provides a starting point for comparing chemical behavior with lighter elements.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
Why compare rutherfordium fluoride behavior with zirconium and hafnium?
Rutherfordium complexes in aqueous separation experiments
FOLLOW THIS RELATIONSHIP
Form a group-based expectation
Rutherfordium shares group 4 with zirconium and hafnium. That relationship suggests a chemical comparison, while leaving the actual behavior of the heavy species to be measured.
Explore the model (optional)
RfFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Optional: check your understanding
USE THE EXPLANATION
How should a measured difference from hafnium be interpreted?
Atomic identity, reference properties and structure models
INTERACTIVE 3D104 visible sites
An electron censusDrag to rotate · scroll or pinch to zoom
[Rn] 5f14 6d2 7s2. Grouping electrons by principal shell connects the neutral-atom configuration to periodic-table patterns.
What this representation means
A three-dimensional counting diagram. Dots are count markers, not measured electron positions; spherical placement and spacing are arbitrary. There are no electron trajectories here. Orbitals describe quantum states.
For superheavy elements, this configuration is a theoretical assignment. It does not establish measured bulk chemistry or a material state.
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HISTORY & HUMAN DISCOVERY
A contested discovery beyond the actinides
Claims for element 104 came from Dubna in 1964 and Berkeley in 1969, beginning a long dispute over evidence and naming. Discovery credit was ultimately shared, and the 1997 settlement adopted rutherfordium in honor of Ernest Rutherford. The element’s scientific importance extends beyond that dispute: it provided a first opportunity to test transition-metal chemistry beyond the actinides using atoms that must be studied before they .
1964–1969
Competing evidence
Dubna and Berkeley experiments contribute to the discovery of element 104.
1997
Name adopted
The international settlement adopts rutherfordium, Rf.
Rutherfordium is manufactured in nuclear reactions at accelerator facilities. There is no established natural deposit and no stock of bulk metal. Chemical experiments work with atoms supplied during the measurement campaign, so repeated individual events build the evidence that an ordinary element might yield in one large sample.
The neutral configuration is a predicted reference for this superheavy atom. Actual chemistry experiments show group 4 behavior but also differences from zirconium and hafnium in particular complexes. Those observations test periodic trends directly; they do not establish an ordinary melting point, hardness or appearance for bulk rutherfordium.
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
CITE THIS PAGE
Family labels and the group-3 layout are teaching conventions. A table position does not establish an unknown bulk property. Electronic configurations refer to neutral atoms; ions and material environments require their own account.
Read each reference property together with its units, conditions and the reference information below.
Not yet recorded: electron affinity, second ionization energy, ground-state term symbol, van der waals radius, thermal conductivity, specific heat capacity, electrical resistivity, crystal structure, lattice parameter a, space group, abundance in seawater, abundance in the universe, annual production, supply-risk listing, hazard classification, biological role, cas registry number, pubchem cid, wikidata item. These families are declared and awaiting an ingestion run against the source each names; they are listed here rather than shown as empty rows.
Physical
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Phase at 20 °C
Not recorded
293.15 K, 101.325 kPa
Melting point
Not recorded
at standard pressure unless noted
Boiling point
Not recorded
101.325 kPa
Density
Not recorded
solids and liquids at 293 K; gases at 273 K and 101.325 kPa
Atomic and electronic
Intended reference: Pauling electronegativity scale · Widely tabulated; original in The Nature of the Chemical Bond
Electronegativity
Not recorded
Pauling scale
First ionization energy
Not recorded
gas-phase neutral atom, ground state
Covalent radius
Not recorded
single-bond covalent radius
Common oxidation states
Not recorded
states met in ordinary compounds; not exhaustive
Occurrence and identity
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Abundance in the crust
Not recorded
upper continental crust, mass fraction
Has stable isotopes
Noderived
Discovery year in CE
1964 CEderived
WHERE IT SITS AMONG ITS NEIGHBORS
Electronegativity across period 7
Ra 0.9 Pauling · Radium
Electronegativity across period 7. Exact values.
Ra
0.9
Ac
1.1
Th
1.3
Pa
1.5
U
1.38
Np
1.36
Pu
1.28
Am
1.13
Cm
1.28
Bk
1.3
Cf
1.3
Es
1.3
Fm
1.3
Md
1.3
No
1.3
Lr
1.3
Electronegativity down group 4
Ti 1.54 Pauling · Titanium
Electronegativity down group 4. Exact values.
Ti
1.54
Zr
1.33
Hf
1.3
The trend uses the same reference-property values as the periodic table. Elements with no recorded value are left out of the line rather than drawn at zero.
