The atomic shell or electron shell is the outer part of an atom that consists of electrons . The division of an atom into an atomic nucleus and an atomic shell goes back to Ernest Rutherford , who in 1911 showed in scattering experiments that atoms consist of a tiny, compact core surrounded by a shell.
Because of the low mass of the electrons, the uncertainty principle means that the atomic shell is about 20,000 to 150,000 times larger than the atomic nucleus . Despite this large spatial expansion, the atomic shell houses only about 1/2000 to 1/6000 of the mass of the entire atom.
The structure of the electron shell largely determines not only the size of the atoms, but also the chemical properties. The outer part of the atomic shell, the valence shell, is responsible for the chemical bonds . The distribution of electrons in the electron shell of an atom to different energy states or lounges (the quantum mechanical model is the atomic orbital ) is dealt with in the articles electron configuration or in the corresponding section of the article atom .
The electron shell of an atom is explained in detail in many introductory books on atomic physics. Examples are mentioned here
- Wolfgang Demtröder: Experimental Physics 3 - Atoms, Molecules and Solids . 4th edition. Springer, 2010, ISBN 978-3-642-03910-2 , doi : 10.1007 / 978-3-642-03911-9 .
- Hermann Haken and Hans C. Wolf: Atomic and Quantum Physics . 8th edition. Springer, 2004, ISBN 3-540-02621-5 .
- atomic shell. In: Spektrum.de. Retrieved May 13, 2020 .