Relative Isotopic Mass



  • Estimating Isotopic Mass. The relative atomic mass of a carbon-12 atom is defined as 12.00 The relative atomic mass of an atom of carbon-13 is found to be 1.08333 times the mass of a carbon-12 atom, that is 1.083 × 12 = 13.00 We can estimate the mass of any isotope of an element, its isotopic mass, using its mass number (A).
  • The experimental relative abundances of (M+1) isotopic ions were evaluated in different data sets. First of all, 137 solutions of commercial compounds were analyzed by flow injection analysis in both the positive and negative ion modes.
  • The relative atomic mass of an element is also known as the relative atomic weight of an element, or, the atomic weight of an element.
  • Relative atomic mass is often abbreviated as r.a.m.
  • The relative atomic mass of an element (its atomic weight) is given in the Periodic Table.
  • Relative atomic mass is determined by the average atomic mass, or the weighted mean of the atomic masses of all the atoms of a particular chemical element found in a particular sample, which is then compared to the atomic mass of carbon-12. This comparison is the quotient of the two weights, which makes the value dimensionless (having no unit).

  • The relative atomic mass of an element is the weighted average of the masses of the isotopes in the naturally occurring element relative to the mass of an atom of the carbon-12 isotope which is taken to be exactly 12.
  • The atomic mass unit (u) is defined as a mass equivalent to 1/12 of the mass of one atom of carbon-12.

    1 u = 1.66 × 10-27 kg

    We can estmate the the relative atomic mass (atomic weight) of an element E with the naturally occurring isotopes aE, bE, cE, etc, and with the respective abundances of A%, BRelative isotopic mass of chlorine%, C% etc,
    relative atomic mass (r.a.m.) = ( A
    100
    × a) + ( B
    100
    × b) + ( C
    100
    × c) + etc
    Given the relative atomic mass (r.a.m.) of an element and the estimated mass of each of its isotopes, we can then estimate the relative abundance of each isotope: let x = %abundance of isotope-a
    and 100 - x = %abundance of isotope-b
    then, let r.a.m = relative atomic mass of the element:
    r.a.m. = ( x
    100
    × mass isotope-a) + ( 100 - x
    100
    × mass isotope-b)
    Isotopic

    and solve for x

  • Note that we can measure the mass of each isotope and its abundance using Mass Spectroscopy
  • Relative
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    relative atomic mass

    How To Calculate Isotopic Mass

    n
    (Chemistry) the ratio of the average mass per atom of the naturally occurring form of an element to one-twelfth the mass of an atom of carbon-12. Symbol: Ar Abbreviation: r.a.m. Former name: atomic weight
    Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

    relative atomic mass

    Relative Isotopic Mass Of Cl

    (atomic weight) The mass (quantity of matter) of atoms.
    Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited

    Relative Isotopic Mass Meaning

    Noun1.relative atomic mass - (chemistry) the mass of an atom of a chemical element expressed in atomic mass units
    atomic mass, atomic weight
    mass - the property of a body that causes it to have weight in a gravitational field
    combining weight, eq, equivalent weight, equivalent - the atomic weight of an element that has the same combining capacity as a given weight of another element; the standard is 8 for oxygen
    meq, milliequivalent - one-thousandth of an equivalent
    chemical science, chemistry - the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions
    Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.

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