Structure of an Atom

The History of the Atom

  1. Democritus (Ancient Greece) – Predict the presence of an atom
  2. Dalton (UK, 1800) – Applied atomic chemistry
  3. Krux (Britain, late 19th century) – Invented a cathode ray tube to explain various phenomena of electrons
  4. Rutherford (Great Britain, 1909) – Confirming the existence of atomic nuclei
  5. J. J. Thomson (UK, 1897) – Determination of the presence of electrons through a cathode ray tube experiment
  6. N. Bohr (Denmark, 1913) – Planetary hypothesis of the atom
  7. A. N. Bohr (Denmark, 1922) – Describing the shape of an atomic nucleus
  8. de Broglie (France, 1923) – Propose the oscillation of electron particles
  9. Schrödinger (Austria, 1926) – Mathematically identifying the electron orbits of an atom
  10. Heisenberg (Germany, 1927) – Describes the stability of the electron orbit through the uncertainty principle
  11. R. Feynman (USA, 1965) – Quantum Mechanics Research
  12. IBM (USA, 1990) – Making a microscope capable of viewing atoms, succeeding in moving atoms into particles

Atomic model

What is the shape of an atom? The ‘atomic model’ is a kind of figure in order to understand the atom. Historically, atomic models have changed as follows.

When we did not know about atoms, we thought that the atoms would be a solid mass like a billiard ball. But real atoms can be divided into electrons and nuclear. In addition, particle accelerators can be used to break down the nuclear.

About 200 years ago, atoms were imagined to be like muffins with raisins. The raisins on the outside of muffins can be likened to electrons. The positive charges in the atom are spread evenly throughout the volume, and the electrons (raisins) are thought to oscillate around the fixed points in the sphere (muffin) of the charge.

In fact, it was discovered 100 years ago by Rutherford that most of the atoms were empty.

Subsequently, Niels Bohr presented a more complementary atomic model. The atomic model of Bohr is very close to these days. In Bohr’s atomic model, electrons are orbiting in a given orbit. This model is also referred to as a planet model because it looks like a planet with electrons circling around the nuclear.

At present, the electrons around the nucleus are known to have both the properties of materials and waves. The position and speed of the electron can not be known at the same time. Electrons are only identified with statistical probabilities.