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104Rf267.000
Transition Metald-blockRadioactive

Rutherfordium

Element 104 on the periodic table, symbol Rf, group 4, period 7.

Rutherfordium is a chemical element with symbol Rf and atomic number 104, named in honor of physicist Ernest Rutherford. It is a synthetic element (an element that can be created in a laboratory but is not found in nature) and radioactive; the most stable known isotope, 267Rf, has a half-life of approximately 1.3 hours. In the periodic table of the elements, it is a d - block element and the second of the fourth - row transition elements.

Properties

Atomic Number
104
Atomic Mass
267.0000 u
Group
4
Period
7
Block
d-block
Category
Transition Metal
State at 25 °C
Solid
Melting Point
2,400 K · 2,126.9 °C
Boiling Point
5,800 K · 5,526.9 °C
Density
23.2 g/cm³
Atomic Radius
Not measured
Electronegativity
Not measured
Oxidation States
+4
Abundance in Crust
Vanishingly rare
Discovered
1964
Discovered By
Joint Institute for Nuclear Research

Electron Configuration

[Rn] 5f14 6d2 7s2

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d2

Ionisation Energies (kJ/mol)

  1. 1. 580

Elements near Rutherfordium

Elements in the same group share the number of outer electrons and behave in similar ways. Elements in the same period share a shell, so they change steadily from left to right.

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