Developing models of atoms

• What do atoms consist of?

  An atom consists of a nucleus containing protons and neutrons, surrounded by electrons in shells.
• How can the numbers of subatomic particles in an atom be calculated?

  The numbers of subatomic particles can be calculated from its atomic number and mass number.
• What is the structure of the atom according to the nuclear model?

  • Nucleus contains protons and neutrons
  • Electrons orbit the nucleus in shells
  • Shells are at certain distances from the nucleus
• Who adapted the nuclear model of the atom?

  Niels Bohr adapted Ernest Rutherford's nuclear model.
• What did Niels Bohr suggest about electrons?

  Bohr suggested that electrons orbit the nucleus in shells.
• What did Bohr's calculations agree with?

  Bohr's calculations agreed with observations from experiments.
• What are protons?

  Protons are subatomic particles with a positive charge and a relative mass of 1.
• What is the relative charge of a proton?

  The relative charge of a proton is +1.
• Who found evidence for neutrons and when?

  James Chadwick found evidence for neutrons in 1932.
• What are neutrons?

  Neutrons are uncharged subatomic particles with a mass of 1 relative to a proton.
• What is the relative charge of a neutron?

  The relative charge of a neutron is 0.
• What led to the development of the modern atomic model?

  • Discovery of protons and neutrons
  • Evidence from experiments supporting Bohr's calculations
  • Understanding of electron arrangement in shells