Rutherfordium – Periodic Table – Atomic Properties



Element Rutherfordium
Atomic number 104
Atomic mass [amu] 261
Atomic mass [pm] 157
Density at STP [g/cm3] 23.2
Number of protons 104
Number of neutrons (typical isotopes) 263,265-267
Number of electrons 104
Electron configuration [Rn] 5f14 6d2 7s2
Oxidation states +4
Electron affinity [kJ/mol]
Electronegativity [Pauling scale]
First ionization energy [eV]

Atomic Number – Protons, Electrons and Neutrons in Rutherfordium

Proton Number - Atomic NumberRutherfordium is a chemical element with atomic number 104 which means there are 104 protons in its nucleus. Total number of protons in the nucleus is called the atomic number of the atom and is given the symbol Z. The total electrical charge of the nucleus is therefore +Ze, where e (elementary charge) equals to 1,602 x 10-19 coulombs.

The total number of neutrons in the nucleus of an atom is called the neutron number of the atom and is given the symbol N. Neutron number plus atomic number equals atomic mass number: N+Z=A. The difference between the neutron number and the atomic number is known as the neutron excess: D = N – Z = A – 2Z.

For stable elements, there is usually a variety of stable isotopes. Isotopes are nuclides that have the same atomic number and are therefore the same element, but differ in the number of neutrons. Mass numbers of typical isotopes of Rutherfordium are 263,265-267.

Atomic Mass of Rutherfordium

Atomic mass of Rutherfordium is 261 u. 

The atomic mass is the mass of an atom. The atomic mass or relative isotopic mass refers to the mass of a single particle, and therefore is tied to a certain specific isotope of an element. The atomic mass is carried by the atomic nucleus, which occupies only about 10-12 of the total volume of the atom or less, but it contains all the positive charge and at least 99.95% of the total mass of the atom. Note that, each element may contain more isotopes, therefore this resulting atomic mass is calculated from naturally-occuring isotopes and their abundance.

Atomic Radius of Rutherfordium

The atomic radius of Rutherfordium atom is 157pm (covalent radius).

Atomic Radius of Chemical Elements

It must be noted, atoms lack a well-defined outer boundary. The atomic radius of a chemical element is a measure of the distance out to which the electron cloud extends from the nucleus. However, this assumes the atom to exhibit a spherical shape, which is only obeyed for atoms in vacuum or free space. Therefore, there are various non-equivalent definitions of atomic radius.

Electrons and Electron Configuration

The number of electrons in an electrically-neutral atom is the same as the number of protons in the nucleus. Therefore, the number of electrons in neutral atom of Rutherfordium is 104. Each electron is influenced by the electric fields produced by the positive nuclear charge and the other (Z – 1) negative electrons in the atom.


Electron configuration of Rutherfordium is [Rn] 5f14 6d2 7s2.

Possible oxidation states are +4.

Density of Rutherfordium

Density of Rutherfordium is 23.2g/cm3.

Typical densities of various substances are at atmospheric pressure.


ρ = m/V

Atomic Masses of Elements

Periodic Table of Elements - atomic mass

Atomic Radii of Elements

Periodic Table of Elements - atomic radius

Densities of Elements

Periodic Table of Elements - density



Electron Affinity – Rutherfordium

Electron affinity of Rutherfordium is — kJ/mol.



X + e → X + energy        Affinity = – ∆H


Electronegativity of Rutherfordium

Electronegativity of Rutherfordium is .


The electronegativity of Rutherfordium is: χ = —

First Ionization Energy of Rutherfordium

First Ionization Energy of Rutherfordium is — eV.


X + energy → X+ + e


A Rutherfordium atom, for example, requires the following ionization energy to remove the outermost electron.

Rf + IE → Rf+ + e        IE = — eV

Electronegativity of Elements

Periodic Table of Elements - electronegativity

Ionization Energy of Elements

Periodic Table of Elements - ionization energy




Properties of other elements

Rutherfordium - Comparison of Atomic Properties

Periodic Table in 8K resolution

Other properties of Rutherfordium