Chemistry Module 2

Chemistry Module 2

1. Atoms, Ions and Compounds

   • Atomic Structure and Isotopes
     • Proton has a +1 charge
     • Electron has a -1 charge
       • This balances the charge of the atom
     • Isotopes are the same element with a different number of neutrons
     • This does not affect the reactions of the element
     • Ions are charged atoms
       • Positive ions (cations), have a lower number of electrons
       • Negative ions (anions), have a larger number of electrons
   • Formulae and Equations
     • Atoms on the left side of the table form cations
     • Atoms on the right side of the table form anions
     • Binary Compound
       • Name
         • Use the name of the first element
         • Change the second elements name to -ide
         • e.g. sodium and oxygen form sodium ox-ide
   • Relative Mass
     • Relative isotopic mass is the mass of an isotope relative to 1/12th the mass of a carbon-12
     • Relative atomic mass, the weighted mean mass of an atom of an element relative to 1/12th the mass of carbon-12
     • The weighted mean mass includes:
       • Percentage abundance of each isotope
       • Relative isotopic mass of each isotope
     • Percentage abundance of an isotope is determined using a mass spectrometer
       • m/z = Relative ion mass / Relative ion charge