Question

What is the oxidation state of magnesium?

Answer 1

Hint :Oxidation state: It is the charge assigned to an atom after gaining or losing electrons. If any atom when lose electrons, then it attains a positive charge i.e., cation is formed and if it gains electrons, then it attains a negative charge i.e., an anion is formed.

Complete Step By Step Answer:
Magnesium is an element represented by the symbol Mg and It is placed in the second group as alkali earth metal in the modern periodic table. Its atomic number is \[12\].
Need to acquire oxidation state: When the electrons are filled in the orbitals, some of the orbitals are not able to achieve stable configuration. For achieving stable configuration i.e., noble gas configuration, an element loses or gains an electron which is indicated as its oxidation state.
For magnesium,
Atomic number of magnesium \[ = 12\]
Electronic configuration of magnesium \[ = 1{s^2}2{s^2}2{p^6}3{s^2}\]
Atomic number of nearest noble gas i.e., Neon \[ = 10\]
Electronic configuration of neon \[ = 1{s^2}2{s^2}2{p^6}\]
Therefore, to achieve noble gas configuration magnesium atoms needs to lose two electrons as follows:
 \[Mg \to M{g^{2 + }} + 2{e^ - }\]
Hence the oxidation state of magnesium is \[ + 2\].

Note :
The electronic configuration of elements should be done by following Aufbau’s Principle and Hund’s Rule. The electrons placed in the outermost shell are considered to be valence electrons and valence electrons are first to leave the atom if any chemical change in an atom takes place.
After removal of two valence electrons from magnesium, the third ionization of magnesium is comparatively high which indicates that magnesium cannot exhibit \[ + 3\]oxidation state due to un-stability.