Question

What is the electron configuration of an $Mn$ atom in the ground state?

Answer 1

Manganese, $Mn$ has the atomic number of $25$. The element does exist as a free element in nature but is often found in a combined state with iron. It is transition metal.

Complete answer:
Since the atomic number of manganese is $25$, its electronic configuration in ground state will be: $1{s^2},2{s^2},2{p^6},3{s^2},3{p^6},4{s^2},3{d^5}$. If we write the electronic configuration with the noble gas configuration then it will be $[Ar]3{d^5}4{s^2}$. We used argon as it is the closest noble gas that has fully filled orbitals.

Additional information:
Manganese is one of the few compounds that can show multiple oxidation states. Some of the common oxidation states of manganese are $+ 2, + 3, + 4, + 6$ and $+ 7$. It is a silvery-grey metal and it resembles iron. It is hard and very brittle in nature but it is easy to oxidize. It slowly tarnishes in air and rusts like iron in water that contains dissolved oxygen.
Manganese is mainly used to decolourize glass and to prepare violet-coloured glass. It is also essential to the iron and steel production due to its sulfur-fixing, deoxidizing and alloying properties. It is a key component of low-cost stainless steel.
Manganese is an essential human dietary element. It is present as a coenzyme in several biological processes like macronutrient metabolism, bone formation and free radical defence systems. However, excessive exposure or intake may lead to a condition called manganism, a neurodegenerative disorder.

Note:
Manganese can show oxidation states from $- 3$to $+ 7$. The above shown oxidation states are some of the most common oxidation states. When it is used with oxidation state $+ 7$, then it acts as a very strong oxidizing agent. For example: permanganate $(M{n_2}{O_7})$.