Plutonium (94)

Here it is - Doc Emmit Brown's element: PLUTONIUM

Plutonium was the second transuranium element of the actinide series to be discovered. By far of greatest importance is the isotope 239Pu, which has a half-life of more than 20000 years. One kilogram is equivalent to about 22 million kilowatt hours of heat energy. The complete detonation of a kilogram of plutonium produces an explosion equal to about 20000 tons of chemical explosive. The various nuclear applications of plutonium are well known. The isotope 233Pu was used in the American Apollo lunar missions to power seismic and other equipment on the lunar surface. Plutonium contamination is an emotive environmental problem.

•Name: Plutonium
•Symbol: Pu
•Atomic number: 94
•Atomic weight: [ 244 ]
•Standard state: solid at 298 K
•CAS Registry ID: 7440-07-5
•Group in periodic table:
•Group name: Actinoid
•Period in periodic table: 7 (actinoid)
•Block in periodic table: f-block
•Color: silvery white
•Classification: Metallic

Historical information
Plutonium was discovered/synthesized by Glenn T. Seaborg , J. W. Kennedy, E. M. McMillan, A. C. Wahl at 1940 in USA,by deuteron bombardment of uranium in a cyclotron (a device used to accelerate atomic particles) at Berkeley, California, USA. Named after the...er, former...planet Pluto. Plutonium was the second transuranium element of the actinide series to be discovered. In 1808 plutonium was suggested as a name for element 56 but Sir Humphrey Davy's original name of barium for element 56 still stands.

Physical properties
•Melting point: 912.5 [or 639.4 °C (1182.9 °F)] K
•Boiling point: 3503 [or 3230 °C (5846 °F)] K
•Density of solid: 19816 kg m-3

Orbital properties
•Ground state electron configuration: [Rn].5f6.7s2
•Shell structure: 2.8.18.32.24.8.2
•Term symbol: 7F0

Neptunium (93)

and now for something completely different ;') The synthetic elements!

Starting with the sea god's element: Neptunium!

Neptunium is a radioactive rare earth metal and has at least 3 allotropic forms. It is named for the planet Neptune. Np-237 is a by-product from nuclear reactors.

•Name: Neptunium
•Symbol: Np
•Atomic number: 93
•Atomic weight: [ 237 ]
•Standard state: solid at 298 K
•CAS Registry ID: 7439-99-8
•Group in periodic table:
•Group name: Actinoid
•Period in periodic table: 7 (actinoid)
•Block in periodic table: f-block
•Color: silvery metallic
•Classification: Metallic

Historical information
Neptunium was discovered by Edwin M. McMillan and P. H. Abelson at 1940 in USA, at Berkeley, California, who bombarded uranium with neutrons produced from a cyclotron.. Named after the planet Neptune, neptunium was the first synthetic transuranium element of the actinide series. It was discovered by McMillan and Abelson in 1940 It was the first synthetic transuranium (elements after uranium) element discovered.

Physical properties
•Melting point: 910 [or 637 °C (1179 °F)] K
•Boiling point: 4300 [or ca. 4000 °C (7232 °F)] K
•Density of solid: 20450 kg m-3

Orbital properties
•Ground state electron configuration: [Rn].5f4.6d1.7s2
•Shell structure: 2.8.18.32.22.9.2
•Term symbol: 6L11/2

Uranium (92)

Aaaannnddd - the last of the naturally occuring elements: URANIUM!

Uranium is of great interest because of its application to nuclear power and nuclear weapons. Uranium contamination is an emotive environmental problem. It is not particularly rare and is more common than beryllium or tungsten for instance.

•Name: Uranium
•Symbol: U
•Atomic number: 92
•Atomic weight: 238.02891 (3) [see notes g m
...•Standard state: solid at 298 K
•CAS Registry ID: 7440-61-1
•Group in periodic table:
•Group name: Actinoid
•Period in periodic table: 7 (actinoid)
•Block in periodic table: f-block
•Color: metallic grey
•Classification: Metallic

Historical information
Uranium was discovered by Martin Klaproth at 1789 in Germany. Named after the planet Uranus, which at the time had just been discovered. A yellow glass containing more than 1% uranium oxide dating back to 79 AD was found near Naples in Italy. Klaproth recognized an unknown element in pitchblende and attempted to isolate the metal in 1789. However, uranium metal itself was first isolated in 1841 by Eugene-Melchoir Peligot, who reduced the anhydrous chloride UCl4 with potassium. The radioactive nature of uranium was not appreciated for another 55 years when in 1896 Henri Becquerel detected its radioactivity.

Uranium gives interesting yellow and green colours and fluorescence effects when included to glass in conjunction with other additives. There is a type of glass manufactured by the Uranium Glass Gallery in Japan, where you can find further information about uranium glass. This type of glass is sometimes referred to as "vaseline glass" in the UK and USA and as "Annagelb" (yellow) or "Annagruen" (green) in Germany. It is a very strange, greenish yellow type of glass that at one point was put into tableware because of the color produced.

Physical properties
•Melting point: 1405.3 [or 1132.2 °C (2070 °F)] K
•Boiling point: 4200 [or ca.3900 °C (7101 °F)] K
•Density of solid: 19050 kg m-3

Orbital properties
•Ground state electron configuration: [Rn].5f3.6d1.7s2
•Shell structure: 2.8.18.32.21.9.2
•Term symbol: 5L6

Well...onward from here it is the synthesized elements....only 26 more until we're done with the periodic table!

Protactinium (91)

Protactinium has a bright metallic luster which it retains for some time in air. The element is superconductive below 1.4 K. The element is a dangerous toxic material and requires precautions similar to those used when handling plutonium. Protactinium is one of the rarest and most expensive naturally occurring elements. The element is an α-emitter and is a radiological hazard similar to polonium. Protactinium is a highly toxic and radioactive rare earth metal that requires special handling. It is found in pitchblende and ores form Zaire and is one of the rarest and most expensive naturally occurring elements.

•Name: Protactinium
•Symbol: Pa
•Atomic number: 91
•Atomic weight: 231.03588 (2)
•Standard state: solid at 298 K
•CAS Registry ID: 7440-13-3
•Group in periodic table:
•Group name: Actinoid
•Period in periodic table: 7 (actinoid)
•Block in periodic table: f-block
•Color: silvery metallic
•Classification: Metallic

Historical information
Protactinium was discovered by Otto Hahn, Lise Meitner, Frederick Soddy, John Cranston at 1913 in Germany, England. Name originates from the Greek word "protos" meaning "first". Protactinium is found in pitchblende and ores form Zaire and is one of the rarest and most expensive naturally occurring elements. Protactinium was identified by Fajans and Gaehring in 1913 who named the new element brevium ("brief"). The metal itself was not isolated until 1934 when Aristid Grosse developed two methods. One involved reduction of the pentoxide Pa2O5 with a stream of electrons in a vacuum and the second involved heating the iodide PaI5 under vacuum.

Physical properties
•Melting point: 1841 [or 1568 °C (2854 °F)] K
•Boiling point: 4300 [or ca. 4000 °C (7232 °F)] K
•Density of solid: 15370 kg m-3

Orbital properties
•Ground state electron configuration: [Rn].5f2.6d1.7s2
•Shell structure: 2.8.18.32.20.9.2
•Term symbol: 4K11/2

Thorium (90)

Quite a bit shorter today..... (I can hear all of the Avenger jokes and comments now...)

Thorium is a source of nuclear power. There is probably more untapped energy available for use from thorium in the minerals of the earth's crust than from combined uranium and fossil fuel sources. Much of the internal heat the earth has been attributed to thorium and uranium.

When pure, thorium is ...a silvery white metal which is air-stable and retains its lustre for several months. When contaminated with the oxide, thorium slowly tarnishes in air, becoming grey and finally black. Thorium oxide has a melting point of 3300°C, the highest of all oxides. Only a few elements, such as tungsten, and a few compounds, such as tantalum carbide, have higher melting points.

Thorium is slowly attacked by water, but does not dissolve readily in most common acids, except hydrochloric. Powdered thorium metal is often pyrophoric (will combust in the presence of air) and should be carefully handled. When heated in air, thorium turnings ignite and burn brilliantly with a white light.

Thorium is named for Thor, the Scandinavian god of war. It is found in thorite and thorianite in New England (USA) and other sites.

Name: Thorium
Symbol: Th
Atomic number: 90
Atomic weight: 232.03806 (2) [see note g]
Standard state: solid at 298 K
CAS Registry ID: 7440-29-1
Group in periodic table:
Group name: Actinoid
Period in periodic table: 7 (actinoid)
Block in periodic table: f-block
Color: silvery white
Classification: Metallic

Historical information
Thorium was discovered by Jöns Berzelius at 1829 in Sweden, given to him by the Reverend Thrane Esmark. Named after "Thor" the mythological Scandinavian god of war and thunder. (NOT the Avenger)

Physical properties
Melting point: 2115 [or 1750 °C (3182 °F)] K
Boiling point: 5093 [or 4820 °C (8708 °F)] K
Density of solid: 11724 kg m-3

Orbital properties
Ground state electron configuration: [Rn].6d2.7s2
Shell structure: 2.8.18.32.18.10.2
Term symbol: 3F2
Pauling electronegativity: 1.3 (Pauling units)
First ionisation energy: 587 kJ mol-1
Second ionisation energy: 1110 kJ mol-1