2.1.1 Atomic structure and isotopes

2.1.1 Atomic structure and isotopes

1. (a) isotopes as atoms of the same element with different numbers of neutrons and different masses

2. (b) atomic structure in terms of the numbers of protons, neutrons and electrons for atoms and ions, given the atomic number, mass number and any ionic charge

3. (c) explanation of the terms relative isotopic mass (mass compared with 1/12th mass of carbon-12) and relative atomic mass (weighted mean mass compared with 1/12th mass of carbon-12), based on the mass of a 12C atom, the standard for atomic masses

4. (d) use of mass spectrometry in:

   • (i) the determination of relative isotopic masses and relative abundances of the isotope
   • (ii) calculation of the relative atomic mass of an element from the relative abundances of its isotopes