Understanding Atoms

Close-up Views of Atoms

• Current Limitations:
  • No direct close-up view of atoms yet.
  • Experiments have allowed the creation of models depicting atomic structures.
  • Colors are used in models for distinguishing different particles, not actual representation.

Structure of an Atom

• Nucleus:

  • Located at the center of an atom.
  • Composed of subatomic particles:
    • Protons:
      • Positive electrical charge.
    • Neutrons:
      • No electrical charge.
      • Similar mass as protons.
  • Overall, the nucleus is positively charged.

• Electrons:

  • Negatively charged particles.
  • Orbit around the nucleus.
  • The size of the negative charge of an electron equals the positive charge of a proton.
  • Move at approximately three-quarters the speed of light.

Forces in the Atom

• Stability:
  • Electrons do not shoot off due to the attraction between positive (protons) and negative (electrons) charges.

Atomic Identification

• Number of Protons and Electrons Define an Atom:
  • Hydrogen Atom:
    • 1 proton, 1 electron.
  • Oxygen Atom:
    • 8 protons, 8 electrons.
  • Iron Atom:
    • 26 protons, 26 electrons.

Conclusion

• Understanding atoms involves the balance and interaction of subatomic particles.
• The simple atomic model is insufficient to explain the behavior and properties of most substances.