Rutherfordium (Rf)

Rutherfordium properties

Atomic number

104

Atomic mass

267 u

Category

Transition metal

Group

4

Period

7

Block

d-block

State at room temp.

Unknown

Electronegativity

—

Melting point

—

Boiling point

—

Density

—

Valence electrons

2

Common charges

+4

Oxidation states

+4

Atomic radius

—

Ionization energy

—

Electron affinity

—

Radioactive

Yes, no stable isotopes

Discovered

1964

Rutherfordium electron configuration

The electron configuration of Rutherfordium (Rf) is [Rn] 5f14 6d2 7s2. Its 104 electrons are arranged in shells as 2, 8, 18, 32, 32, 10, 2.

Protons, neutrons and electrons in Rutherfordium

A neutral Rutherfordium atom has 104 protons and 104 electrons. Most Rutherfordium atoms have about 163 neutrons: the atomic mass rounded to 267, minus the atomic number 104.

Neutrons are approximate: atoms of the same element can have different numbers of neutrons (isotopes). Atomic number and mass

How many valence electrons does Rutherfordium have?

2

Rutherfordium has 2 valence electrons, counting the electrons in its outermost s subshell. Like most transition metals, it can also use d electrons in bonding.

See every element: Periodic table with valence electrons

Rutherfordium orbital diagram

Each box is an orbital that holds up to two electrons with opposite spins (↑↓). The inner shells are the same as the noble gas in brackets. How to write electron configurations

Molar mass of Rutherfordium

267 g/mol

One mole of Rutherfordium atoms (6.022 × 10²³ atoms) has a mass of 267 grams. Use this value to convert between grams and moles.

Rutherfordium facts

• Rutherfordium was the first transactinide element, the first element beyond the actinide series.
• Soviet scientists wanted to call it kurchatovium; the name rutherfordium was only agreed on in 1997 after a long naming dispute.
• Rutherfordium (Rf) has atomic number 104. It was discovered in 1964.

Position in the periodic table

Rutherfordium is element 104, in period 7 and group 4 of the periodic table, in the d-block.

All transition metals

Uses of Rutherfordium

Rutherfordium has no uses outside research because only a few atoms can be made at a time. Chemists use it to test whether the periodic table still works for superheavy elements. Single-atom experiments show that it behaves broadly like zirconium and hafnium, the lighter elements in group 4, as its position in the table predicts.

Who discovered Rutherfordium?

A team led by Georgy Flerov at the Joint Institute for Nuclear Research in Dubna, Soviet Union, first claimed rutherfordium in 1964, and Albert Ghiorso's group at Berkeley reported it in 1969; credit is shared. It is named after Ernest Rutherford, who pioneered the study of the atomic nucleus.

Where does the name come from?

Rutherfordium honors Ernest Rutherford, the New Zealand-born physicist who discovered the atomic nucleus and is often called the father of nuclear physics. The name was officially approved in 1997 after a long naming dispute.

Discovery timeline