the nucleur model

• Nuclear model of atomic structure


  Most of an atom is empty space, with a positive nucleus containing most of the mass, and negative electrons at the edge
• Nuclear model


  • Electrons orbit the nucleus at specific distances (energy levels/shells)
  • Positive charge in nucleus due to protons
  • Nucleus also contains neutral particles called neutrons
• Radius of an atom is around 0.1 nanometer
• Radius of the nucleus is approximately 1 * 10^-14 m
• Nearly all the mass of an atom is found in the nucleus
• Relative charge


  The charge of one particle compared to another particle
• Relative charge of particles

  • Protons: +1
  • Neutrons: 0
  • Electrons: -1
• Atoms have no overall charge because the number of electrons equals the number of protons
• Relative mass


  The mass of one particle compared to another particle
• Relative mass of particles

  • Protons: 1
  • Neutrons: 1
  • Electrons: much smaller than 1
• what did neils bore propose

  that electrons orbited the nucleus at specific distances
• what was neils bore proposal accepted

  because it agreed with the results of other scientists
• what did scientists find sever years after neils bore proposal

  that the positive charge in the nuleus is due to tiny positive particles called protons
• what discovery did james chadwick make 20 years after

  that nucleus contains neutral paticles called neutrons