• Atomic Number
  The number of protons in an atom determines which element it is.  For example all atoms that have 6 protrons are carbon atoms.  This is because the number of protrons in an atom determines the quantized electrical energy levels outside the atom which determine the chemical behaviour.  The number of protons of an atom is often referred to as the atomic number of an atom since the number of protons uniquely identifies the element.
• Atomic Symbol:
  The atomic symbol is one or two letters that represent the element.  These symbols are used internationally.   Typically a symbol is the truncated name of the element or the truncated Latin name of the element. Click Here for a list of the elements and their symbols.
• Atomic Mass:
  The atomic mass is the average mass of an element in atomic mass units (amu).  Though individual atoms always have an integer number of amus, the atomic mass is a decimal number due to different the various isotopes.  The average number of neutrons for an element can be found by subtracting the number of protrons (atomic number) from the atomic mass.
• Electron Configuration:
  The electron configuration is the orbital description of the locations of the electrons in an unexcited atom.  Using principles of physics, chemists can predict how atoms will react and likely properties of compounds such as stability, boiling point, and conductivity.  Typically only the outermost electron shells matter in chemistry so we truncate the inner electron shell notation by replacing the long hand orbital description with a noble gas in brackets.  This method of notation vastly simplifies the description for large molecules. 
  Example:  The electron configuration for Be is 1s22s2 but we write [He]2s2 where [He] is equivalent to all the electron orbitals in the Helium atom.

Further explanation of the atom may be found Here.