This tool calculates the ground state electronic structure of the 118 chemical elements of Mendeleyev's periodic table. It details the following data :
- Z or the atomic number
- Abbreviated electronic configuration
- Complete electronic configuration
- Number of layers
- Number of electrons per layer
The atomic electronic configuration is important to know because it helps us understand the position a chemical element occupies in the periodic table as well as its relationship with the elements that occupy the same row or column. Also, the electronic configuration is related to the chemical properties of the element.
The standard notation to represent the electronic configuration of an atom details the number of electrons present in each sub layer. For example, the electronic configuration of the oxygen atom is written: 1s2 2s2 2p4 . This means that there are two electrons in sublayer 1s , two electrons in sub-layer 2s and four electrons in the sub layer 2p.
Short form vs long form
The standard notation becomes very long for some atoms. For example, for radium (chemical symbol: Ra) it is written 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4d10 4f14 5s2 5p6 5d10 6s2 6p6 7s2, which is not very convenient... Phycisians and chemists use in this case a short form (or abbreviated form) which consists in using the closest noble chemical element which has the same configuration as the heart of the atom to be represented. In the case of Radium, Radon (noble element of Rn symbol) is used and the abbreviated radium formula is then written [Rn] 7s2 which is much simpler.