Electronic configuration abbreviated notation

An abbreviated way of presenting electron configuration is to write the principal quantum number and letter of each occupied orbital and then use a superscript to indicate the number of electrons in each orbital. The orbitals of each atom are then written in order of increasing energy levels. For the group 1 elements, this notation is... 

Write the electron configuration for uranium, U (atomic number 92), in abbreviated notation. 

Using the abbreviated notation, give the electron configuration for strontium, Sr (atomic number 38). 

In writing electron configurations of atoms, we frequently simphfy the notations. The abbreviation [He] indicates that the It orbital is completely fiUed, Is, as in hehum. 

The electron configurations for elements beyond these first 18 become long and tedious to write. We often abbreviate the electron configuration using the following notation ... 

With this notation, the electron configuration of element number 11, sodium, may be shown as NelSsi, which is an abbreviation for The former notation... 

Discuss the possible electronic configurations of elements 118 and 154. Predict their chemical behavior by extrapolation of known properties of their lower homologs in the periodic table. For simplicity, an abbreviated notation such as [Rn]6d 7s maybe used to describe the electronic configuration of element 89 (actinium). Using the (n+C) rule as a guide, work out the electronic configuration of element 103 (lawrencium) and proceed from there. 

With this notation, the electron configuration of element number 11, sodium may be shown as Ne 35, which is an abbreviation for 15 25 2/7 35. The former notation has some advantage in simplicity, while showing the outer electrons specifically. In the example just cited it is easy to see that sodium has 1 outer shell 35 electron, which it can lose to form the Na ion with its stable noble gas neon electron configuration. 

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