Nmero atmicoNombreSmboloPeriodo,Grupopeso atmico(uma)Densidad(g/cm)a20CPunto de fusin(C)Punto de ebullicin(C)Ao de sudescubrimientoDescubridor

1HidrgenoH1, 11.00794(7) 0.084 g/l-259.1-252.691766T. Von Hohenheim (Paracelso)

2HelioHe1, 184.002602(2) 0.17 g/l-272.2-268.91895RamsayyCleve

3LitioLi2, 16.941(2 0.53180.513171817Arfwedson

4BerilioBe2, 29.012182(3)1.85127829701797Vauquelin

5BoroB2, 1310.811(7) 2.46230025501808DavyyGay-Lussac

6CarbonoC2, 1412.0107(8) 3.5135504827PrehistoriaDesconocido

7NitrgenoN2, 1514.0067(2) 1.17 g/l-209.9-195.81772Rutherford

8OxgenoO2, 1615.9994(3) 1.33 g/l-218.4-182.91774PriestlyyScheele

9FlorF2, 1718.9984032(5)1.58 g/l-219.6-188.11886Moissan

10NenNe2, 1820.1797(6) 0.84 g/l-248.7-246.11898RamsayyTravers

11SodioNa3, 122.98976928(2)0.9797.88921807Davy

12MagnesioMg3, 224.3050(6)1.74648.811071755Black

13AluminioAl3, 1326.9815386(8)2.70660.524671825Oersted

14SilicioSi3, 1428.0855(3) 2.33141023551824Berzelius

15FsforoP3, 1530.973762(2)1.8244 (P4)280(P4)1669Brand

16AzufreS3, 1632.065(5) 2.06113444.7PrehistoriaDesconocido

17CloroCl3, 1735.453(2) 2.95 g/l-34.6-1011774Scheele

18ArgnAr3, 1839.948(1) 1.66 g/l-189.4-185.91894RamsayyRayleigh

19PotasioK4, 139.0983(1)0.8663.77741807Davy

20CalcioCa4, 240.078(4) 1.5483914871808Davy

21EscandioSc4, 344.955912(6)2.99153928321879Nilson

22TitanioTi4, 447.867(1)4.51166032601791GregoryKlaproth

23VanadioV4, 550.9415(1)6.09189033801801del Ro

24CromoCr4, 651.9961(6)7.14185724821797Vauquelin

25ManganesoMn4, 754.938045(5)7.44124420971774Gahn

26HierroFe4, 855.845(2)7.8715352750PrehistoriaDesconocido

27CobaltoCo4, 958.933195(5)8.89149528701735Brandt

28NquelNi4, 1058.6934(2)8.91145327321751Cronstedt

29CobreCu4, 1163.546(3) 8.921083.52595PrehistoriaDesconocido

30ZincZn4, 1265.409(4)7.14419.6907PrehistoriaParacelso

31GalioGa4, 1369.723(1)5.9129.824031875Lecoq de Boisbaudran

32GermanioGe4, 1472.64(1)5.32937.428301886Winkler

33ArsnicoAs4, 1574.92160(2)5.72613613(sublimacin)ca. 1250Albertus Magnus

34SelenioSe4, 1678.96(3) 4.822176851817Berzelius

35BromoBr4, 1779.904(1)3.14-7.358.81826Balard

36KriptnKr4, 1883.798(2) 3.48 g/l-156.6-152.31898RamsayyTravers

37RubidioRb5, 185.4678(3) 1.53396881861BunsenyKirchhoff

38EstroncioSr5, 287.62(1) 2.6376913841790Crawford

39ItrioY5, 388.90585(2)4.47152333371794Gadolin

40CirconioZr5, 491.224(2) 6.51185243771789Klaproth

41NiobioNb5, 592.906 38(2)8.58246849271801Hatchett

42MolibdenoMo5, 695.94(2) 10.28261755601778Scheele

43TecnecioTc5, 7[98.9063] 11.49217250301937PerrierySegr

44RutenioRu5, 8101.07(2) 12.45231039001844Klaus

45RodioRh5, 9102.90550(2)12.41196637271803Wollaston

46PaladioPd5, 10106.42(1) 12.02155231401803Wollaston

47PlataAg5, 11107.8682(2) 10.49961.92212PrehistoriaDesconocido

48CadmioCd5, 12112.411(8) 8.643217651817StrohmeyeryHermann

49IndioIn5, 13114.818(3)7.31156.220801863ReichyRichter

50EstaoSn5, 14118.710(7) 7.292322270PrehistoriaDesconocido

51AntimonioSb5, 15121.760(1) 6.69630.71750PrehistoriaDesconocido

52TeluroTe5, 16127.60(3) 6.25449.69901782von Reichenstein

53YodoI5, 17126.90447(3)4.94113.5184.41811Courtois

54XennXe5, 18131.293(6) 4.49 g/l-111.9-1071898RamsayyTravers

55CesioCs6, 1132.9054519(2)1.9028.46901860KirchhoffyBunsen

56BarioBa6, 2137.327(7)3.6572516401808Davy

57LantanoLa6138.90547(7) 6.1692034541839Mosander

58CerioCe6140.116(1) 6.7779832571803W. HisingeryBerzelius

59PraseodimioPr6140.90765(2)6.4893132121895von Welsbach

60NeodimioNd6144.242(3) 7.00101031271895von Welsbach

61PrometioPm6[146.9151] 7.22108027301945MarinskyyGlendenin

62SamarioSm6150.36(2) 7.54107217781879Lecoq de Boisbaudran

63EuropioEu6151.964(1) 5.2582215971901Demaray

64GadolinioGd6157.25(3) 7.89131132331880de Marignac

65TerbioTb6158.92535(2)8.25136030411843Mosander

66DisprosioDy6162.500(1) 8.56140923351886Lecoq de Boisbaudran

67HolmioHo6164.93032(2)8.78147027201878Soret

68ErbioEr6167.259(3) 9.05152225101842Mosander

69TulioTm6168.93421(2)9.32154517271879Cleve

70IterbioYb6173.04(3) 6.9782411931878de Marignac

71LutecioLu6, 3174.967(1) 9.84165633151907Urbain

72HafnioHf6, 4178.49(2)13.31215054001923Costeryde Hevesy

73TantalioTa6, 5180.9479(1)16.68299654251802Ekeberg

74WolframioW6, 6183.84(1)19.26340759271783Elhuyar

75RenioRe6, 7186.207(1)21.03318056271925Noddack,TackeyBerg

76OsmioOs6, 8190.23(3) 22.61304550271803Tennant

77IridioIr6, 9192.217(3)22.65241041301803Tennant

78PlatinoPt6, 10195.084(9)21.45177238271557de Ulloa

79OroAu6, 11196.966569(4)19.321064.42940PrehistoriaDesconocido

80MercurioHg6, 12200.59(2)13.55-38.9356.6PrehistoriaDesconocido

81TalioTl6, 13204.3833(2)11.85303.614571861Crookes

82PlomoPb6, 14207.2(1)11.34327.51740PrehistoriaDesconocido

83BismutoBi6, 15208.98040(1)9.80271.415601540Geoffroy

84PolonioPo6, 16[208.9824] 9.202549621898MarieyPierre Curie

85AstatoAt6, 17[209.9871] 3023371940CorsonyMacKenzie

86RadnRn6, 18[222.0176] 9.23 g/l-71-61.81900Dorn

87FrancioFr7, 1[223.0197] 276771939Perey

88RadioRa7, 2[226.0254] 5.5070011401898MarieyPierre Curie

89ActinioAc7[227.0278] 10.07104731971899Debierne

90TorioTh7232.03806(2) 11.72175047871829Berzelius

91ProtactinioPa7231.03588(2) 15.37155440301917Soddy,CranstonyHahn

92UranioU7238.02891(318.971132.438181789Klaproth

93NeptunioNp7[237.0482] 20.4864039021940McMillanyAbelson

94PlutonioPu7[244.0642] 19.7464133271940Seaborg

95AmericioAm7[243.0614] 13.6799426071944Seaborg

96CurioCm7[247.0703] 13.5113401944Seaborg

97BerkelioBk7[247.0703] 13.259861949Seaborg

98CalifornioCf7[251.0796] 15.19001950Seaborg

99EinstenioEs7[252.0829] 8601952Seaborg

100FermioFm7[257.0951] 1952Seaborg

101MendelevioMd7[258.0986] 1955Seaborg

102NobelioNo7[259.1009] 1958Seaborg

103LaurencioLr7, 3[260.1053] 1961Ghiorso

104RutherfordioRf7, 4[261.1087] 1964/69Flerov

105DubnioDb7, 5[262.1138] 1967/70Flerov

106SeaborgioSg7, 6[263.1182] 1974Flerov

107BohrioBh7, 7[262.1229] 1976Oganessian

108HassioHs7, 8[265] 1984GSI(*)

109MeitnerioMt7, 9[266] 1982GSI

110DarmstadtioDs7, 10[269] 1994GSI

111RoentgenioRg7, 11[272] 1994GSI

112CopernicioCn7, 12[285] 1996GSI

113UnuntrioUut7, 13[284] 2004JINR(*),LLNL(*)

114FlerovioFl7, 14[289] 1999JINR

115UnunpentioUup7, 15[288] 2004JINR,LLNL

116LivermorioLv7, 16[290] 2006JINR,LLNL(**)

117UnunseptioUus7, 172009-2010JINR

118UnunoctioUuo7, 18[294]52006JINR,LLNL(**)