Period 8 element

The eighth period of the extended periodic table of elements contains all the chemical elements that have exactly eight electrons in the atomic shells. It is in this period to a date yet theoretical continuation of the periods of the periodic table. There are currently no proven chemical element that period. Theoretically, the innermost (first) electron shell is fully occupied and has two electrons. The second electron shell with eight electrons, the third electron shell with 18 electrons and the fourth electron shell with 32 electrons are also fully occupied. The fifth electron shell has at least 32 electrons and can hold up to 50 electrons. The sixth electron shell has 18 electrons and can accommodate a maximum of 32 electrons. The seventh electron shell has at least 8 electrons and can hold up to 18 electrons. The outermost (eighth ) electron shell, also called valence shell, can accommodate between one and eight electrons. Thus, there is theoretically a total of 50 chemical elements in the eighth period. The chemical elements 139-153 are grouped according to Glenn T. Seaborg to the Superactinoiden and represent a special group within this period since. A special feature of this period is the occupation of the g - orbital with electrons, this g - orbital occurs only from this period.

Excerpt from the extended periodic table

Note: The color Coral ( # FF7F50 ) for the Superactinoide is just for distinction within this article.

Chemical and physical properties

The elements should probably half-lives in the area have a few nanoseconds. The therefore assumed lifetime of an element of the 8th period is too short that it could enter into a chemical reaction. In that regard, should the elements of the 8th period have no defined chemical properties.

Magic Number

At least two of the period -8 elements, namely 120 ( Unbinilium ) and 126 ( Unbihexium ) have a magical atomic number. This means that at its core the shells are fully occupied. Since such nuclei are energetically more favorable than those with incomplete occupied shells, one suspects that some isotopes, especially Unbinilium -304 and Unbihexium -310, form islands of stability and therefore have longer half-lives than similarly sized isotopes of other elements. These two isotopes are doubly magic, that is, in addition to the number of protons is also the number of neutrons a magic number.

Number of electrons in the electron shells

The following information is currently still just a theory and may change at any time by new findings, they should therefore be treated with extreme caution.

List

Since there is still no proven chemical element of the eighth period, all names and symbols are provisional only. They correspond to the IUPAC rules for a systematic element name. Also, the classification of the elements 121-153 in the Superactinoide is only temporary. The following information is currently still just a theory and may change at any time by new findings, they should therefore be treated with extreme caution.

Note: The color Coral ( # FF7F50 ) for the Superactinoide, only for better differentiation within this article.

Trivia

In the Star Trek universe, the elements 121 and 145 under the name Tritanium or Duraniumbekannt.