Rutherfordium

Rutherfordium, ₁₀₄Rf

Rutherfordium
Pronunciation	/ˌrʌðərˈfɔːrdiəm/ ⓘ ​(RUDH-ər-FOR-dee-əm)
Mass number	[267]
Rutherfordium in the periodic table
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Hf ↑ Rf ↓ (Upo) lawrencium ← rutherfordium → dubnium
Atomic number (Z)	104
Group	group 4
Period	period 7
Block	d-block
Electron configuration	[Rn] 5f14 6d2 7s2[1][2]
Electrons per shell	2, 8, 18, 32, 32, 10, 2
Physical properties
Phase at STP	solid (predicted)[1][2]
Melting point	2400 K ​(2100 °C, ​3800 °F) (predicted)[1][2]
Boiling point	5800 K ​(5500 °C, ​9900 °F) (predicted)[1][2]
Density (near r.t.)	17 g/cm3 (predicted)[3][4]
Atomic properties
Oxidation states	(+2), (+3), +4[1][2][5] (parenthesized: prediction)
Ionization energies	1st: 580 kJ/mol 2nd: 1390 kJ/mol 3rd: 2300 kJ/mol (more) (all but first estimated)[2]
Atomic radius	empirical: 150 pm (estimated)[2]
Covalent radius	157 pm (estimated)[1]
Other properties
Natural occurrence	synthetic
Crystal structure	​hexagonal close-packed (hcp) (predicted)[6]
CAS Number	53850-36-5
History
Naming	after Ernest Rutherford
Discovery	Joint Institute for Nuclear Research and Lawrence Berkeley National Laboratory (1969)
Isotopes of rutherfordium v e
Main isotopes[7] Decay abun­dance half-life (t1/2) mode pro­duct 261Rf synth 2.1 s SF82% – α18% 257No 263Rf synth 15 min[8] SF<100%? Preview warning: Infobox Rf isotopes: Decay mode percentage not recognised "perc1=<100%?" cat#% – α~30%? Preview warning: Infobox Rf isotopes: Decay mode percentage not recognised "perc2=~30%?" cat#% 259No 265Rf synth 1.1 min[9] SF – 267Rf synth 48 min[10] SF –
Category: Rutherfordium view talk edit | references

Rutherfordium is a synthetic chemical element; it has symbol Rf and atomic number 104. It is named after physicist Ernest Rutherford. As a synthetic element, it is not found in nature and can only be made in a particle accelerator. It is radioactive; the most stable known isotope, ²⁶⁷Rf, has a half-life of about 48 minutes.

In the periodic table, it is a d-block element and the second of the fourth-row transition elements. It is in period 7 and is a group 4 element. Chemistry experiments have confirmed that rutherfordium behaves as the heavier homolog to hafnium in group 4. The chemical properties of rutherfordium are characterized only partly. They compare well with the other group 4 elements, even though some calculations had indicated that the element might show significantly different properties due to relativistic effects.

In the 1960s, small amounts of rutherfordium were produced at Joint Institute for Nuclear Research in the Soviet Union and at Lawrence Berkeley National Laboratory in California.^[11] Priority of discovery and hence the name of the element was disputed between Soviet and American scientists, and it was not until 1997 that the International Union of Pure and Applied Chemistry (IUPAC) established rutherfordium as the official name of the element.