Question

What is the shorthand electron configuration of Au?

Answer 1

The atomic number of gold in the periodic table of elements is $79$.
Shorthand is used for abbreviated and easier symbolic writing of electron configuration. It makes the electron configuration easy to read, write and understand.

Complete answer:
Electron configuration of any element gives information about the occupied electron orbitals for any given element. The properties of the outer shell of an element help in determining the behaviour of a particular element. Three main parts of electron configuration are:
Number that tells about the energy level
Letter that tells about the specific orbital
Superscript number that tells about the number of electrons in that particular orbital
The shorthand electron configuration of an element in a given period involves starting with the symbol of noble gas appearing in the previous period of periodic table and the symbol of noble gas is followed by the additional configuration of electrons of given element.
Shorthand electron configuration of gold (Au) is given as: $\left[ Xe \right]\text{ }4{{f}^{14}}~5{{d}^{10}}~6{{s}^{1}}$
The nearest noble gas to gold (Au) is Xeon due to which it appears in the electron configuration of Au and also both Xeon and gold (Au) share the same electron configuration due to which [Xe] appears in the electron configuration of Au.
The electron configuration starts with the symbol of noble gas in the previous period because electron configuration of a given element is dependent on the electron configuration of noble gas.

Note:
Atomic number of given element is equal to the number of protons in the nuclei of atoms of element.