Atomic structure

• The atom


  • Electrons
  • Protons
  • Neutrons
• Electrons have a charge of -1
• Protons have a charge of +1
• Neutrons have a charge of 0
• Electrons have a mass of 1/2000 of the mass of a proton
• The space between the nucleus and electrons is very large
• 99% of the atom is empty space
• Everything is made up of atoms
• Democritus had the idea that everything was made up of atomos

  460BC
• John Dalton proposed that elements have different atoms


  1803
• JJ Thompson's atomic model

  • Atoms were balls of positive charge with negative charges
• Rutherford's atomic model


  • Discovered the nucleus and that most of the atom is empty space
• Bohr's atomic model


  • Electrons come in more than one shell
• Chadwick's discovery


  • Evidence of neutrons in the nucleus