Atomic model

By sebaspapasmamao
  • 400 BCE

    Democritus

    Democritus
    Democritus's model stated that matter consists of invisible particles called atoms and a void.
    Main contribution: Was the one who discover the atom
    How was the model wrong? It doesn´t have electrons, protons and neutrons.

  • Dalton (Billiard ball)

    Dalton (Billiard ball)
    Dalton said that the atom was the smallest particle of matter, so he thought it was a solid sphere.
    Main contribution: that all compounds were composed of combinations of these atoms in defined ratios.
    How was the model wrong? It doesn´t have electron, neutron or protons.

  • Thompson (Plumpudding)

    Thompson (Plumpudding)
    The atom is composed of electrons surrounded by a soup of positive charge to balance the electrons
    Main contribution: The discovery of electrons.
    How was the model wrong? That it was a giant ball with electrons around it.

  • Rutherford (Planetary model)

    Rutherford (Planetary model)
    His atom model is mostly empty space, with electrons orbiting a positively charged nucleus. Rutherford conducted his gold foil experiment. In the experiment, many alpha particles bounced off of the foil, suggesting that there was something positive colliding with the alpha particles.
    Main contribution: It demonstrate that the atom has a nucleus and the electrons are orbiting it.
    How was the model wrong? The main problem with the model was that he couldn't explain why electrons stay in orbit.

  • Bohr (1915)

    Bohr (1915)
    Is a planetary model in which the negatively charged electrons orbit a small, positively charged nucleus
    Main contributions
    Electrons orbit the nucleus in orbits that have a set size and energy.
    The energy of the orbit is related to its size.
    •The Bohr Model explains the Rydberg formula How was the model wrong?
    Violates the Heisenberg Uncertainty Principle.
    It makes poor predictions regarding the spectra of larger atoms.
    It does not explain the Zeeman Effect.

  • Schrödinger (Electron cloud)

    Schrödinger (Electron cloud)
    This model is a nucleus surrounded by an electron cloud. Where the cloud is most dense, the probability of finding the electron is more.
    Main contribution: He used mathematical equations to describe the probability of finding an electron in a position. the model does not define the exact path of an electron, but , predicts the possibilities of the location of the electron. this model introduced the concept of sub-energy levels.
    How was the model wrong: the Schrodinger’s equation is useless.