104RfRutherfordium[267]

A real sample of the element Rutherfordium — Synthetic element — no real sample has ever been photographed

Rutherfordium (Rf)

“Born into a thirty-year Cold War feud: the Soviets called it kurchatovium, the Americans rutherfordium, and IUPAC only ruled in 1997.”

View group 4 →View period 7 →See in trends →

Atomic number104

Atomic mass[267]

Group4

Period7

BlockD-block

PhaseSolid

Electron structure

How its electrons are arranged

[Rn] 5f¹⁴ 6d² 7s²

Shell 1

2e⁻

Shell 2

8e⁻

Shell 3

18e⁻

Shell 4

32e⁻

Shell 5

32e⁻

Shell 6

10e⁻

Shell 7

2e⁻

Computed from the aufbau principle, with known real-world exceptions applied automatically.

🎯 Exam focus

Questions to practise

Try each question yourself first — then open it to read the full model answer.

1In which years and at which two rival laboratories was element 104 first claimed, and with which fusion reactions?

Model answerIn 1964 the Soviet JINR at Dubna claimed element 104, slamming neon-22 into plutonium-242 and naming it kurchatovium. In 1969 Albert Ghiorso’s Berkeley team independently made other isotopes by bombarding californium-249 with carbon-12, proposing the name rutherfordium. The two claims, from two Cold War rivals, opened the thirty-year “Transfermium Wars” over elements 104 to 106.

2How does single-atom rutherfordium chemistry help test whether the periodic law still holds for superheavy elements?

Model answerChemists make a handful of rutherfordium atoms and immediately race them through automated chemistry. If the atoms form the compounds their column predicts — volatile $\mathrm{RfCl_{4}}$ , matching hafnium’s tetrachloride, and the expected complex ions in solution — then group relationships survive even in a superheavy atom, and the periodic law holds at the table’s edge.

3While studying Rutherford’s gold-foil experiment in your textbook, which element’s name should remind you of that physicist?

Model answerRutherfordium. While the textbook explains how alpha particles bouncing off gold foil revealed the nucleus, element 104 quietly carries that physicist’s name forward: Ernest Rutherford, father of nuclear physics. So the gold-foil lesson and the Period 7, Group 4 cell of the chart commemorate the same man.

4Compare the roughly hour-long half-life of Rf-267 with the second-scale isotopes used in the earliest chemistry studies.

Model answerRf-267, surviving roughly an hour, is the row’s slowpoke — long enough for comparatively relaxed chemical work on a handful of atoms. The second-scale isotopes of the earliest studies allowed no such luxury: from atom’s birth to finished separation, everything had to run fully automated within seconds, atom by atom.

5Place rutherfordium precisely (group, period, block) and name its closest chemical partner among the lighter Group 4 metals.

Model answerRutherfordium sits in Group 4, Period 7, d-block — the first transactinide, directly below titanium, zirconium and hafnium. Its closest chemical partner is hafnium: atom-by-atom experiments show it behaving like a very heavy hafnium, forming volatile $\mathrm{RfCl_{4}}$ and hafnium-like complex ions in solution.

6Why did the names kurchatovium and rutherfordium battle for three decades before IUPAC’s 1997 verdict?

Model answerBecause both laboratories had genuinely produced the element, and both names honoured national heroes — Dubna proposed kurchatovium after Igor Kurchatov, head of the Soviet atomic project, while Berkeley proposed rutherfordium after Ernest Rutherford. With Cold War pride invested on both sides, neither would yield, so elements 104–106 carried rival names until IUPAC’s 1997 ruling fixed rutherfordium, dubnium and seaborgium.

Quick answers

One fact, one page

Every key fact of this element has its own clean page — a direct two-line answer first, then the working. Fast to load, easy to share.

Electron configurationThe full arrangement, step by step ValencyHow many bonds it forms Atomic massThe standard weight, explained Metal or nonmetalWhich family it belongs to Everyday usesWhere you meet it daily

Your progress

You have explored 0 of 118 elements

Study

The notes

About the element

Characteristics

The first transactinide element: a synthetic, fiercely radioactive transition metal opening Period 7’s d-block in Group 4, below titanium, zirconium and hafnium.
Its chemistry, studied atom by atom, confirms it behaves like a very heavy hafnium — forming volatile $\mathrm{RfCl_{4}}$ and complex ions in solution.
The longest-lived isotope Rf-267 survives about an hour; most other isotopes decay within seconds.
Relativistic effects tweak its electron orbitals slightly, so it is not a perfect hafnium copy — precisely what chemists are eager to probe.

Appearance

Nobody has ever collected enough rutherfordium to see it — experiments work with single atoms. It is predicted to be a dense, hard, silvery transition metal resembling its Group 4 partners zirconium and hafnium, though bent by strong relativistic effects.

Real world

Where you meet it

✦ Uses

Testing the limits of the periodic law: single-atom rutherfordium chemistry checks whether group relationships survive in superheavy atoms.
Benchmarking gas-phase and aqueous separation methods for everything beyond Z = 104 — techniques proven on Rf are reused for Sg, Bh and Hs.
Nuclear spectroscopy: the alpha-decay chains of its isotopes help map the approach toward the predicted island of stability.

◍ Everyday examples

Every NCTB science student meets Rutherford through the gold-foil alpha-scattering experiment — element 104 carries that name forward.
The rutherfordium-versus-kurchatovium standoff is a favourite case study in how international naming disputes in science get resolved.

Story

History & name

Soviet scientists at Dubna’s JINR struck first in 1964, reporting element 104 after slamming neon-22 into plutonium-242 and naming it kurchatovium after Igor Kurchatov, head of the Soviet atomic project. In 1969 Albert Ghiorso’s Berkeley team independently made other isotopes by bombarding californium-249 with carbon-12, proposing the name rutherfordium after Ernest Rutherford. Their quarrel over elements 104 to 106 — the famous “Transfermium Wars” — ended only in 1997, when IUPAC fixed the names used today: rutherfordium, dubnium and seaborgium.

Name originHonours Ernest Rutherford, father of nuclear physics and discoverer of the atomic nucleus.

Neighbours

Nearby elements

The elements that sit right beside this one on the table — often the closest chemical cousins.

102NoNobelium[259]103LrLawrencium[262]105DbDubnium[268]106SgSeaborgium[269]