Question

What is pseudo inert gas configuration:

Answer 1

An inert gas is a gas that does not undergo chemical reactions under a set of given conditions. The noble gases often do not react with many substances and were historically referred to as the inert gases. Inert gases are used generally to avoid unwanted chemical reactions like oxidation or hydrolysis that degrade a sample.

Complete answer:
The configuration of an ion of an element in which the shell with the highest energy level has $18$ electrons instead of $8$ electrons is called Pseudo inert gas configuration. Elements having $d -$ orbital also filled along with the $s$ and $p -$orbital are said to have pseudo gas configuration. More specifically, the element which has fully filled $d -$orbitals $(n - 1){d^{10}}$ and the configuration is not the same as the noble gas configuration, then it is called a pseudo-noble gas configuration.
Cations with pseudo inert gas configuration, that is, $n{s^2}{p^6}{d^{10}}$ or with inert pair configuration, that is, ${d^{10}}(n + 1){s^2}$, have effective nuclear charge (ENC) than cations with noble gas configuration, $n{s^2}{p^6}$. For Example: silver has ${e^ - }$ configuration of $[Ar]5{s^1}4{d^{10}}$. After losing one electron, its configuration becomes $[Ar]4{d^{10}}$, which is a pseudo inert gas configuration.

Note:
Food is packed in inert gas to remove oxygen gas. This prevents bacteria from growing. It also prevents chemical oxidation by oxygen in normal air. Historical documents may also be stored under an inert gas to avoid degradation. Some gases which are not usually considered inert but which behave like inert gases in all the circumstances likely to be encountered in some use can often be used as a substitute for an inert gas.