Atomic Structure

Atomic Structure

1. Made up of:

   • Nucleus
     • Protons
       • Relative Mass:
         • 1
       • Relative Charge
         • +1
     • Neutrons
       • Relative Mass:
         • 1
       • Relative Charge:
         • 0
   • Electrons
     • Orbiting central nucleus on electron shells
     • Relative Mass:
       • 1/1836 or neglegable
     • Relative Charge:
       • -1

2. Terms:

   • Atomic Number
     • How many PROTONS there are in an atom
   • Mass Number
     • The TOTAL number of PROTONS and NEUTRONS in a atom
   • Isotopes
     • DIFFERENT atomic forms of the SAME ELEMENT, which has the SAME number of PROTONS but DIFFERENT number of NEUTRONS
   • Relative atomic mass (Ar)
     • The weighted average of the ISOTOPES of an element compared to 1/12 the mass of a carbon 12 atom

3. The periodic table is arranged in order of the elements' atomic number

4. Isotopic abundance

   • Tells us the AMOUNT of each ISOTOPE
   • A sample of chlorine contains 75 atoms of chlorine in every hundred atoms and 25 atoms of chlorine 37
     • Abundance = 75% and 25%
     • RAM = (75x35) + (25x37) / 100
       • RAM = 35.5
   • You can work out the relative atomic mass of an element using this by:
     • (Abundance x Isotope) + (Abundance x Isotope) all divided by 100