Rutherford model

File:Stylised Lithium Atom .png

A stylised representation of the Rutherford model of a lithium atom

The Rutherford model of the atom was devised by Ernest Rutherford. He performed his famous gold foil experiment (1909), which showed that the Plum pudding model ( of J. J. Thomson) of the atom was incorrect. In the experiment, Rutherford allowed alpha particles to pass through a thin piece of gold foil. He predicted that most of the particles would pass through the foil or be deflected slightly. This is what happened most of the time, but a few particles, 1 in 8000, bounced back towards the source. This proved that atoms have a dense, positive inner core instead of spread-out positive field. In 1911, Rutherford came forth with his own model. In it, the atom is made up of a nucleus surrounded by a cloud of orbiting electrons. However, the Rutherford model did not attribute any structure to the orbiting electrons. The Rutherford model of the atom was soon superseded by the Bohr atom, which used some of the early quantum mechanical results to give structure to the orbiting electrons.

The Rutherford model was very important because it proposed the concept of the nucleus. After the discovery of the Rutherford model, the study of the atom branched into two separate fields, nuclear physics which studies the nucleus of the atom, and atomic physics which studies the structure of the orbiting electrons.

Symbolism

Despite its inaccuracy, the Rutherford model caught the imagination of the public in a way that the more correct Bohr model did not, and has continually been used as a symbol for atoms and atomic energy, even by physicists who should know better. Examples of its use over the past century include:

• The flag of the International Atomic Energy Agency is a Rutherford atom, enclosed in olive branches.
• The US minor league baseball Albuquerque Isotopes' logo is a Rutherford atom, electron orbits forming the "A."
• The Unicode Miscellaneous Symbols codepoint U+269B (⚛), ATOM SYMBOL, uses a Rutherford atom.
• On maps, it is generally used to indicate a nuclear installation.

Key points of Rutherford model

• There is empty space between the electron clouds and the nucleus.
• The atom's positive charges are all calculated in the nucleus.
• The positively charged particles in the nucleus are called protons and mass of a proton is nearly 1840 times greater than

an electrons.Which means nucleus constitutes most of the entire atom.

See also

• Atomic nucleus

External links

• World Of Atoms - "Rutherford's Model"
• Rutherford's Model
• Rutherford's Model