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A Periodic Table of the Elements at Los Alamos National LaboratoryLos Alamos National Laboratory's Chemistry Division PresentsPeriodic Table of the ElementsA Resource for Elementary, Middle School, and High School StudentsClick an element for more 082IIA2A34H13 14 15 16 17IIIA IVA VA VIA VIIA3A 4A 5A 6A 7A5Li Be6.9419.0121112Na Mg22.9924.31192067892He4.00310B C N O F Ne10.81 12.01 14.01 16.00 19.00 20.1834 56789 10 11 12IIIB IVB VB VIB VIIB ------- VIIIIB IIB3B 4B 5B 6B 7B1B2B------------- 8 ------21222324252627282930131415161718Al Si P S Cl Ar26.98 28.09 30.97 32.07 35.45 39.95313233343536K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr39.1040.083738Rb Sr85.4787.62555644.96 47.88 50.94 52.00 54.94 55.85 58.47 58.69 63.55 65.39 69.72 72.59 74.92 78.96 79.90 83.8039404142434445464748495051525354Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe88.91 91.22 92.91 95.94 (98)5772737475101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.37677787980818283848586Cs Ba La* Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn132.9137.38788138.9 178.5 180.9 183.9 186.2 190.2 190.2 195.1 197.0 200.5 204.4 207.2 209.0 (210) (210) (222)112114116118Fr Ra Ac Rf Db Sg Bh Hs Mt --- --- ------------()()()(223)(226)89104 105106107108109(227) (257) (260) (263) (262) (265) (266)http://pearl1.lanl.gov/periodic/ (1 of 3) [5/17/2001 4:06:20 PM]110()111()()

A Periodic Table of the Elements at Los Alamos National Laboratory58Lanthanide Series*59606162636465666768697071Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu140.1 140.9 144.2 (147) 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.0 175.090Actinide Series 919293949596979899100101102103Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr232.0 (231) (238) (237) (242) (243) (247) (247) (249) (254) (253) (256) (254) (257)** Groups are noted by 3 notation conventions.For a list of a the element names and symbols in alphabetical order, click hereDownload this Web Site to your computer (Adobe Acrobat format - PDF)Get Adobe Acrobat Reader for freeQuestions - Comments - FeedbackSend an email to [email protected] is the Periodic Table?How to use the Periodic TableClick here to see Mendeleev's original PeriodicTableChemistry in a NutshellNaming New Elements[ LANL DOE Disclaimer ]Last Updated: 5/10/2001http://pearl1.lanl.gov/periodic/ (2 of 3) [5/17/2001 4:06:20 PM]

A Periodic Table of the Elements at Los Alamos National Laboratoryabout this resourcehttp://pearl1.lanl.gov/periodic/ (3 of 3) [5/17/2001 4:06:20 PM]

HydrogenHydrogenFor rocket fuelAtomic Number:1Atomic Symbol:HAtomic Weight:1.0079Electron Configuration: 1s1History(Gr. hydro, water, and genes, forming) Hydrogen was prepared many years before it was recognized as adistinct substance by Cavendish in 1776.Named by Lavoisier, hydrogen is the most abundant of all elements in the universe. The heavier elementswere originally made from Hydrogen or from other elements that were originally made from Hydrogen.SourcesHydrogen is estimated to make up more than 90% of all the atoms or three quarters of the mass of theuniverse. This element is found in the stars, and plays an important part in powering the universe throughboth the proton-proton reaction and carbon-nitrogen cycle -- stellar hydrogen fusion processes thatrelease massive amounts of energy by combining Hydrogen to form Helium.Production of hydrogen in the U.S. alone now amounts to about 3 billion cubic feet per year. Hydrogen isprepared by steam on heated carbon, decomposition of certain hydrocarbons with heat, action of sodium or potassium hydroxide on aluminum electrolysis of water, or displacement from acids by certain metals.Liquid hydrogen is important in cryogenics and in the study of superconductivity, as its melting point isonly 20 degrees above absolute zero.Tritium is readily produced in nuclear reactors and is used in the production of the hydrogen bomb.Hydrogen is the primary component of Jupiter and the other gas giant planets. At some depth in theplanet's interior the pressure is so great that solid molecular hydrogen is converted to solid .html (1 of 3) [5/17/2001 4:06:21 PM]

Hydrogenhydrogen.In 1973, a group of Russian experimenters may have produced metallic hydrogen at a pressure of 2.8Mbar. At the transition the density changed from 1.08 to 1.3 g/cm3. Earlier, in 1972, at Livermore,California, a group also reported on a similar experiment in which they observed a pressure-volumepoint centered at 2 Mbar. Predictions say that metallic hydrogen may be metastable; others havepredicted it would be a superconductor at room temperature.CompoundsAlthough pure Hydrogen is a gas we find very little of it in our atmosphere. Hydrogen gas is so lightthat uncombined Hydrogen will gain enough velocity from collisions with other gases that they willquickly be ejected from the atmosphere. On earth, hydrogen occurs chiefly in combination with oxygenin water, but it is also present in organic matter such as living plants, petroleum, coal, etc. It is present asthe free element in the atmosphere, but only to the extent of less than 1 ppm by volume. The lightest ofall gases, hydrogen combines with other elements -- sometimes explosively -- to form compounds.UsesGreat quantities are required commercially for the fixation of nitrogen from the air in the Haber ammoniaprocess and for the hydrogenation of fats and oils. It is also used in large quantities in methanolproduction, in hydrodealkylation, hydrocracking, and hydrodesulfurization. Other uses include rocketfuel, welding, producing hydrochloric acid, reducing metallic ores, and filling balloons.The lifting power of 1 cubic foot of hydrogen gas is about 0.07 lb at 0C, 760 mm pressure.The Hydrogen Fuel cell is a developing technology that will allow great amounts of electrical power tobe obtained using a source of hyrogen gas.Consideration is being given to an entire economy based on solar- and nuclear-generated hydrogen.Public acceptance, high capital investment, and the high cost of hydrogen with respect to today's fuels arebut a few of the problems facing such an economy. Located in remote regions, power plants wouldelectrolyze seawater; the hydrogen produced would travel to distant cities by pipelines. Pollution-freehydrogen could replace natural gas, gasoline, etc., and could serve as a reducing agent in metallurgy,chemical processing, refining, etc. It could also be used to convert trash into methane and ethylene.FormsQuite apart from isotopes, it has been shown that under ordinary conditions hydrogen gas is a mixture oftwo kinds of molecules, known as ortho- and para-hydrogen, which differ from one another by the spinsof their electrons and nuclei.Normal hydrogen at room temperature contains 25% of the para form and 75% of the ortho form. Theortho form cannot be prepared in the pure state. Since the two forms differ in energy, the physicalproperties also differ. The melting and boiling points of parahydrogen are about 0.1oC lower than thoseof normal 1.html (2 of 3) [5/17/2001 4:06:21 PM]

HydrogenIsotopesThe ordinary isotope of hydrogen, H, is known as Protium, the other two isotopes are Deuterium (aproton and a neutron) and Tritium (a protron and two neutrons). Hydrogen is the only element whoseisotopes have been given different names. Deuterium and Tritium are both used as fuel in nuclear fusionreactors. One atom of Deuterium is found in about 6000 ordinary hydrogen atoms.Deuterium is used as a moderator to slow down neutrons. Tritium atoms are also present but in muchsmaller proportions. Tritium is readily produced in nuclear reactors and is used in the production of thehydrogen (fusion) bomb. It is also used as a radioactive agent in making luminous paints, and as a tracer.Sources: CRC Handbook of Chemistry and Physics and the American Chemical Society.Last Updated: 12/19/97, CST Information Services l (3 of 3) [5/17/2001 4:06:21 PM]

HeliumHeliumFor blimpsAtomic Number:2Atomic Symbol:HeAtomic Weight:4.00260Electron Configuration: 1s2History(Gr. helios, the sun). Janssen obtained the first evidence of helium during the solar eclipse of 1868 whenhe detected a new line in the solar spectrum. Lockyer and Frankland suggested the name helium for thenew element. In 1895 Ramsay discovered helium in the uranium mineral clevite while it wasindependently discovered in cleveite by the Swedish chemists Cleve and Langlet at about the same time.Rutherford and Royds in 1907 demonstrated that alpha particles are helium nuclei.SourcesExcept for hydrogen, helium is the most abundant element found through out the universe. Helium isextracted from natural gas. In fact, all natural gas contains at least trace quantities of helium.It has been detected spectroscopically in great abundance, especially in the hotter stars, and it is animportant component in both the proton-proton reaction and the carbon cycle, which account for theenergy of the sun and stars.The fusion of hydrogen into helium provides the energy of the hydrogen bomb. The helium content ofthe atmosphere is about 1 part in 200,000. While it is present in various radioactive minerals as a decayproduct, the bulk of the Free World's supply is obtained from wells in Texas, Oklahoma, and Kansas.The only known helium extraction plants, outside the United States, in 1984 were in Eastern Europe(Poland), the USSR, and a few in India.CostThe cost of helium fell from 2500/ft3 in 1915 to 1.5 cents /ft3 in 1940. The U.S. Bureau of Mines has setthe price of Grade A helium at 37.50/1000 ft3 in ml (1 of 3) [5/17/2001 4:06:22 PM]

HeliumPropertiesHelium has the lowest melting point of any element and is widely used in cryogenic research because itsboiling point is close to absolute zero. Also, the element is vital in the study of super conductivity.Using liquid helium, Kurti and co-workers and others, have succeeded in obtaining temperatures of a fewmicrokelvins by the adiabatic demagnetization of copper nuclei.It has other peculiar properties. Helium is the only liquid that cannot be solidified by lowering thetemperature. It remains liquid down to absolute zero at ordinary pressures, but it can readily be solidifiedby increasing the pressure. Solid 3He and 4He are unusual in that both can be changed in volume bymore than 30% by applying pressure.The specific heat of helium gas is unusually high. The density of helium vapor at the normal boilingpoint is also very high, with the vapor expanding greatly when heated to room temperature. Containersfilled with helium gas at 5 to 10 K should be treated as though they contained liquid helium due to thelarge increase in pressure resulting from warming the gas to room temperature.While helium normally has a 0 valence, it seems to have a weak tendency to combine with certain otherelements. Means of preparing helium difluoride have been studied, and species such as HeNe and themolecular ions He and He have been investigated.IsotopesSeven isotopes of helium are known: Liquid helium (He4) exists in two forms: He4I and He4II, with asharp transition point at 2.174K. He4I (above this temperature) is a normal liquid, but He4II (below it) isunlike any other known substance. It expands on cooling; its conductivity for heat is enormous; andneither its heat conduction nor viscosity obeys normal rules.Uses as an inert gas shield for arc welding;a protective gas in growing silicon and germanium crystals and producing titanium and zirconium;as a cooling medium for nuclear reactors, andas a gas for supersonic wind tunnels.A mixture of helium and oxygen is used as an artificial atmosphere for divers and others working underpressure. Different ratios of He/O2 are used for different depths at which the diver is operating.Helium is extensively used for filling balloons as it is a much safer gas than hydrogen. One of the recentlargest uses for helium has been for pressuring liquid fuel rockets. A Saturn booster, like the type used onthe Apollo lunar missions, required about 13 million ft3 of helium for a firing, plus more for checkouts.Liquid helium's use in magnetic resonance imaging (MRI) continues to increase as the medicalprofession accepts and develops new uses for the equipment. This equipment has eliminated some needfor exploratory surgery by accurately diagnosing patients. Another medical application uses MRE tohttp://pearl1.lanl.gov/periodic/elements/2.html (2 of 3) [5/17/2001 4:06:22 PM]

Heliumdetermine (by blood analysis) whether a patient has any form of cancer.Helium is also being used to advertise on blimps for various companies, including Goodyear. Otherlifting gas applications are being developed by the Navy and Air Force to detect low-flying cruisemissiles. Additionally, the Drug Enforcement Agency is using radar-equipped blimps to detect drugsmugglers along the United States boarders. In addition, NASA is currently using helium-filled balloonsto sample the atmosphere in Antarctica to determine what is depleting the ozone layer.CostsMaterials which become super conductive at higher temperatures than the boiling point of helium couldhave a major impact on the demand for helium. These less costly refrigerant materials could replace thepresent need to cool superconductive materials to the boiling point of helium.Sources: CRC Handbook of Chemistry and Physics and the American Chemical Society.Last Updated: 12/19/97, CST Information Services l (3 of 3) [5/17/2001 4:06:22 PM]

LithiumLithiumFor pacemaker batteriesAtomic Number:3Atomic Symbol:LiAtomic Weight:6.941Electron Configuration: [He]2s1History(Gr. lithos, stone) Discovered by Arfvedson in 1817. Lithium is the lightest of all metals, with a densityonly about half that of water.SourcesIt does not