chemistry

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An element with relative atomic mass 20.8 is found to contain 2 isotopes having a relative atomic mass of 20 and 21.Find the % composition of the element.

  • chemistry -

    Relative atomic mass = 20.8 g

    Let the fraction that is element 20 = x
    thus the fraction that is element 21=1-x

    so 20x +21(1-x) = 20.8

    20x + 21 -21x=20.8

    -1x=-0.2

    x=0.2 and 1-x=0.8

    so 20% element 20 and 80% element 21.

  • chemistry -

    20.8%

  • chemistry -

    44%

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