Determiacion Del Peso Molecular Y La Densidad Del Butano

ATOMIC MASSES AND ABUNDANCES
This table lists the mass (in atomic mass units, symbol u) and the natural abundance (in percent) of the stable nuclides and a few important radioactive nuclides. A complete table of all nuclides may be found in Section 10 (“Table of the Isotopes”). The atomic masses were taken from the 1995 evaluation of Audi and Wapstra (References 2, 3). Mass values were roundedin accordance with the stated uncertainty. The number in parentheses following the mass value is the uncertainty (specifically, the rounded value of the estimated standard deviation) in the last digit given. Natural abundance values are also followed by uncertainties in the last digit(s) of the stated values. This uncertainty includes both the estimated measurement uncertainty and the reportedrange of variation in different terrestrial sources of the element (see Reference 4 for more details). A * in the Abundance column indicates a radioactive nuclide not present in nature or an element whose isotopic composition varies so widely that a meaningful natural abundance cannot be defined.

REFERENCES
1. Holden, N. E., “Table of the Isotopes”, in Lide, D. R., Ed., CRC Handbook of Chemistryand Physics, 79th Ed., CRC Press, Boca Raton, FL, 1998. 2. Audi, G. and Wapstra, A. H., Nucl. Phys., A595, 409, 1995. 3. Audi, G. and Wapstra, A. H., Atomic Mass Data Center, World Wide Web site, . Note that the print version in Reference 2 gives mass excess in energy units but not the actual atomic mass. The latter is included in the electronic version. 4. IUPAC Commission on Atomic Weights andIsotopic Abundances, Pure Appl. Chem., 63, 991, 1991. Z 1 1 1 2 2 3 3 4 5 5 6 6 6 7 7 8 8 8 9 10 10 10 11 12 12 12 13 14 14 14 15 16 16 16 16 17 17 18 18 Isotope
1H 2H 3H 3He 4He 6Li 7Li 9Be 10B 11B 12C 13C 14C 14N 15N 16O 17O 18O 19F 20Ne 21Ne 22Ne 23Na 24Mg 25Mg 26Mg 27Al 28Si 29Si 30Si 31P 32S 33S 34S 36S 35Cl 37Cl 36Ar 37Ar

Mass in u 1.007 825 032(1) 2.014 101 778(1) 3.016 049 268(1) 3.016029 310(1) 4.002 603 250(1) 6.015 122 3(5) 7.016 004 0(5) 9.012 182 1(4) 10.012 937 0(3) 11.009 305 5(5) 12 by definition 13.003 354 838(1) 14.003 241 988(4) 14.003 074 005(1) 15.000 108 898(1) 15.994 914 622(2) 16.999 131 5(2) 17.999 160 4(9) 18.998 403 21(8) 19.992 440 176(2) 20.993 846 74(4) 21.991 385 5(2) 22.989 769 7(2) 23.985 041 9(2) 24.985 837 0(2) 25.982 593 0(2) 26.981 538 4(1) 27.976926 533(2) 28.976 494 72(3) 29.973 770 22(5) 30.973 761 5(2) 31.972 070 7(1) 32.971 458 5(1) 33.967 866 8(1) 35.967 080 9(3) 34.968 852 71(4) 36.965 902 60(5) 35.967 546 3(3) 36.966 775 9(3)

Abundance in % 99.985(1) 0.015(1) * 0.000137(3) 99.999863(3) 7.5(2) 92.5(2) 100 19.9(2) 80.1(2) 98.90(3) 1.10(3) * 99.634(9) 0.366(9) 99.762(15) 0.038(3) 0.200(12) 100 90.48(3) 0.27(1) 9.25(3) 100 78.99(3)10.00(1) 11.01(2) 100 92.23(1) 4.67(1) 3.10(1) 100 95.02(9) 0.75(4) 4.21(8) 0.02(1) 75.77(7) 24.23(7) 0.337(3) *

Z 18 18 18 19 19 19 20 20 20 20 20 20 21 22 22 22 22 22 23 23 24 24 24 24 25 26 26 26 26 27 28 28 28 28 28 29 29 30 30

Isotope
38Ar 39Ar 40Ar 39K 40K 41K 40Ca 42Ca 43Ca 44Ca 46Ca 48Ca 45Sc 46Ti 47Ti 48Ti 49Ti 50Ti 50V 51V 50Cr 52Cr 53Cr 54Cr 55Mn 54Fe 56Fe 57Fe 58Fe 59Co 58Ni 60Ni61Ni 62Ni 64Ni 63Cu 65Cu 64Zn 66Zn

Mass in u 37.962 732 2(5) 38.964 313(5) 39.962 383 123(3) 38.963 706 8(3) 39.963 998 7(3) 40.961 826 0(3) 39.962 591 1(3) 41.958 618 3(4) 42.958 766 8(5) 43.955 481 1(9) 45.953 693(3) 47.952 534(4) 44.955 910(1) 45.952 629(1) 46.951 764(1) 47.947 947(1) 48.947 871(1) 49.944 792(1) 49.947 163(1) 50.943 964(1) 49.946 050(1) 51.940 512(2) 52.940 654(2) 53.938885(1) 54.938 050(1) 53.939 615(1) 55.934 942(1) 56.935 399(1) 57.933 280(1) 58.933 200(2) 57.935 348(2) 59.930 791(2) 60.931 060(2) 61.928 349(2) 63.927 970(2) 62.929 601(2) 64.927 794(2) 63.929 147(2) 65.926 037(2)

Abundance in % 0.063(1) * 99.600(3) 93.2581(44) 0.0117(1) 6.7302(44) 96.941(18) 0.647(9) 0.135(6) 2.086(12) 0.004(3) 0.187(4) 100 8.0(1) 7.3(1) 73.8(1) 5.5(1) 5.4(1) 0.250(2)...