The Nuclear Model

• What is the nuclear model of atomic structure?

  The nuclear model describes an atom with a positive nucleus containing most of its mass and negative electrons surrounding it.
• How did the nuclear model replace the Plum Pudding model?

  The nuclear model replaced the Plum Pudding model due to the results of the alpha scattering experiment.
• What modifications were made to the nuclear model after its initial proposal?

  • Electrons orbit the nucleus at specific energy levels or shells
  • Protons were discovered as positive particles in the nucleus
  • Neutrons were discovered as neutral particles in the nucleus
• Who proposed that electrons orbit the nucleus at specific distances?

  Neils Bohr proposed that electrons orbit the nucleus at specific distances.
• What determines the positive charge in the nucleus?

  The positive charge in the nucleus is due to protons.
• How many protons does a hydrogen atom have?

  A hydrogen atom has one proton.
• How many protons does a helium atom have?

  A helium atom has two protons.
• What is the significance of the number of protons in an atom?

  The number of protons determines the positive charge in the nucleus and the element's identity.
• Who discovered neutrons?

  James Chadwick discovered neutrons.
• What are the approximate sizes of an atom and its nucleus?

  • Radius of an atom: approximately 0.1 nanometers (1 * 10^-10 m)
  • Radius of the nucleus: approximately 1 * 10^-14 m
• What is the relative charge of protons, neutrons, and electrons?

  Protons: +1, Neutrons: 0, Electrons: -1
• Why do atoms have no overall charge?

  Atoms have no overall charge because the number of protons equals the number of electrons.
• What is the relative mass of protons and neutrons?

  Both protons and neutrons have a relative mass of 1.
• How does the relative mass of electrons compare to protons and neutrons?

  Electrons have a much smaller relative mass than protons and neutrons.
• What is the significance of relative charge and relative mass in atomic structure?

  • Relative charge indicates the charge of one particle compared to another
  • Protons: +1, Neutrons: 0, Electrons: -1
  • Relative mass indicates the mass of one particle compared to another
  • Protons and Neutrons: relative mass of 1, Electrons: much smaller