?Ž5DD/ g   +  Elementy 1Symbol Atomic no. Atomic weightSpecific gravityMelting point deg CBoiling point deg C # of isotopes DiscovererYear˙<HydrogenH11.00800.070-259.14-252.873 Cavendish1766˙;HeliumHe24.002600.1785-272.2-268.9345Janssen1868˙7LithiumLi36.9410.534180.5413475 Arfvedson1817˙> BerylliumBe49.012181.848 12278+/-529706 Vauquelin1798˙DBoronB510.812.37230025506Gay-Lussac and Thenard; Davy1808˙4CarbonC612.0111.8-3.5-355048277 Prehistoric˙=NitrogenN714.00670.808-209.86-195.88 Rutherford1772˙9OxygenO815.99941.14-218.4-182.9628Priestly1774˙;FluorineF918.99841.108-219.62-188.146Moissan1886˙FNeonNe1020.1790.89990-248.67-246.0488Ramsay and Travers1898˙;SodiumNa1122.98980.971 97.81+/-0.03882.97Davy1807˙< MagnesiumMg1224.3051.738 648.8+/-0.510908Black1755˙9AluminumAl1326.98152.6989660.3724678Wohler1827˙6SiliconSi1428.0862.33141023558 Berzelius1824˙4 PhosphorusP1530.97381.8244.12807Brand1669˙4SulfurS1632.062.07112.844.67410 Prehistoric˙:ChlorineCl1735.4531.56-100.98-34.611Scheele1774˙DArgonAr1839.9481.7837-189.2-185.78Rayleigh and Ramsay1894˙4 PotassiumK1939.1020.86263.6577410Davy1807˙4CalciumCa2040.081.55839+/-2148414Davy1808˙7ScandiumSc2144.95592.9891539283215Nilson1879˙8TitaniumTi2247.904.55 1660+/-1032879Gregor1791˙:VanadiumV2350.94146.11 1890+/-1033809del Rio1801˙AChromiumCr2451.996 7.18-7.20 1857+/-2026729 Vauquelin1797˙S ManganeseMn2554.9380 7.21-7.441244+/-3196211Gahn,Scheelem and Bergman1774˙2IronFe2655.8477.8941535275010 Prehistoric˙3CobaltCo2758.93328.91495287014Brandt1735˙6NickelNi2858.718.9021453273211 Cronstedt1751˙;CopperCu2963.5468.96 1083.4+/-.02256711 Prehistoric˙2ZincZn3065.387.133419.5890715 Prehistoric˙:GalliumGa3169.725.90429.78240314 Boisbaudran1875˙8 GermaniumGe3272.595.323937.4283017Winkler1886˙CArsenic (gray)As3374.92165.7381761314Albertus Magnus1250˙;SeleniumSe3478.964.79217 684.9+/-120 Berzelius1817˙5BromineBr3579.9043.12-7.258.7819Balard1826˙LKryptonKr3683.803.733-156.6-152.30+/-0.1023Ramsay and Travers1898˙BRubidumRb3785.46781.53238.8968820Busen and Kirchoff1861˙2 StrontiumSr3887.622.54769138418Davy1808˙9YttriumY3988.90594.4571523+/-833721Gadolin1794˙< ZirconiumZr4091.226.5061852+/-2437720Klaproth1789˙HNiobium (Columbium)Nb4192.90648.57 2468+/-10474224Hatchett1801˙8 MolybdenumMo4295.9410.222617461220Scheele1778˙D TechnetiumTc4398.906211.502172487723Perrier and Segre1937˙6 RutheniumRu44101.0712.442310390016Klaus1844˙DRhodiumRh45102.905512.411966+/-3 3727+/-10020 Wollaston1803˙9 PalladiumPd46106.412.021552314021 Wollaston1803˙7SilverAg47107.86810.50961.93221227 Prehistoric˙7CadmiumCd48112.408.65320.976522 Stromeyer1817˙@IndiumIn49114.827.31156.61208034Reich and Richter1863˙4TinSn50118.697.31231.9681227028 Prehistoric˙AAntimonySb51121.756.691630.74175029Early historic times˙N TelluriumTe52127.606.24 449.5+/-0.3 989.8+/-3.829von Reichenstein1782˙9IodineI53126.90454.93113.5184.3524Courtois1811˙FXenonXe54131.303.52-111.9 -107.1+/-331Ramsay and Travers1898˙ECesiumCs55132.90551.87328.40678.422Bunsen and Kichhoff1860˙/BariumBa56137.343.5725164025Davy1808˙? LanthanumLa57138.90556.166920+/-5345419 Monsander1839˙PCeriumCe58140.126.771798+/-3325719Berzelius and Hisinger;Klaproth1803˙E PraseodymiumPr59140.90776.772931+/-4321215 von Weisbach1885˙D NeodymiumNd60144.24 6.80 & 7.0041010312716 von Welsbach1885˙; PromethiumPm61145~10802460?14Marinsky et al.1945˙>SamariumSm62150.47.5361072+/-5177817 Boisbaudran1879˙;EuropiumEu63151.965.283822+/-5159721Demarcay1896˙> GadoliniumGd64157.257.8981311+/-1323317Marignac1880˙>TerbiumTb65158.92548.2341360+/-4304124 Monsander1843˙= DysprosiumDy66162.508.5401409233521 Boisbaudran1886˙GHolmiumHo67164.93038.7811470272029Delafontaine and Soret1878˙6ErbiumEr68167.269.0451522251016Mosander1843˙;ThuliumTm69168.93429.314 1545+/-15172718Cleve1879˙< YtterbiumYb70173.046.972824+/-5119316Marignac1878˙:LutetiumLu71174.979.8351656+/-5331522Urbain1907˙IHafniumHf72178.4913.31 2227+/-20460217Coster and von Hevesy1923˙@TantalumTa73180.947916.6542996 5425+/-10019Ekeberg1801˙PTungsten (Wolfram)W74183.88519.3 3410+/-20566022J. and F. d'Elhyar1783˙GRheniumRe75186.221.0231.80562721Noddack, Berg, and Tacke1925˙?OsmiumOs76190.222.57 3045+/-30 5027+/-10019Tennant1803˙5IridiumIr77192.2222.422410413025Tennat1803˙;PlatinumPt78195.0921.451772 3827+/-10032Ulloa1735˙7GoldAu79196.966519.321064.43280721 Prehistoric˙:MercuryHg80200.5913.546-38.87356.5826 Prehistoric˙=ThalliumTl81204.3711.85303.5 1457+/-1028Crookes1861˙4LeadPb82207.211.35327.502174029 Prehistoric˙>BismuthBi83208.98069.747271.31560+/-519Geoffroy1753˙/PoioniumPo842109.3225496234Curie1898˙4AstatineAt85-21030233721 Corson et al.1940˙,RadonRn862224.4-71-61.820Dorn1900˙*FranciumFr872232767721Perey1939˙=RadiumRa88226.02545.0?700114015P. and M. Curie1898˙;ActiniumAc8922710.071050 3200+/-30011Debierne1899˙:ThoriumTh90232.038111.721750479012 Berzelius1828˙C ProtactiniumPa91231.035915.37<166014Hahn and Meitner1917˙?UraniumU92238.029-18.95 1132.3+/-0.8381815Peligot1841˙J NeptuniumNp93237.048220.25640+/-1390215McMillan and Abelson1940˙; PlutoniumPu9424419.84641323216Seaborg et al.1940˙? AmericiumAm9524313.67994+/-4260713Seaborg et al.1944˙:CuriumCm9624713.51 1340+/-4013Seaborg et al.1944˙2 BerkeliumBk9724714.00‚8Seaborg et al.1949˙/ CaliforniumCf98251ƒ12Seaborg et al.1950˙. EinsteiniumEs99254ƒ12 Ghiorso et al1952˙+FermiumFm100257ƒ10 Ghiorso et al1953˙/ MendeleviumMd101256ƒ3Ghiorso et al.1955˙,NobeliumNo102254ƒ7Ghiorso et al.1957˙/ LawrenciumLr103257ƒ20Ghiorso et al.1961˙˙˙