Atomic Structure

• What is an Element

  a substance that is made up from one atom type
• What is a compound

  a substance made from two or more types of atoms
• What is relative atomic mass


  The average mass of an isotope using the abundance (how common it is) of the isotopes
• Relative atomic mass calculation:

  (MN of Isotope 1 * its percent abundance) + (MN of isotope 2 * its percent abundance)

  all divided by 100
• Relative atomic mass example

  
• Electronic structure is the arrangement of electrons in an atom or molecule.

  (where on the rings they are)
• Atomic number


  Determines the element
• Protons (P)


  Determine the element
• Neutrons (N)


  Only affect the mass number
• Relative atomic mass (Ar)


  The average mass of the atoms of an element, taking into account the masses and abundances of the isotopes
• Electronic shells


  Energy levels where electrons are found
• The mass number is the protons + neutrons