Question

Electronic configuration of a transition element X in +2 oxidation state is [Ar]3d^5 what is its atomic number

Answer 1

Answer:

(43)ar3d'5 ,atomic state

Answer 2

Answer:

The atomic number of the element X in $+2$ oxidation state with an electronic configuration of  $[Ar]3d^5$ is $25.$

Explanation:

It is given that,

The Transition element X is in its $+2$ oxidation state and have an electronic configuration of $[Ar]3d^5$·

We know that an oxidation state represents "the total number of electrons that an element loses or gains"· It becomes a positive charge when it loses electrons and a negative charge when it gains electrons· Here, the element X has $+2$ oxidation state which means that the element X already loses two electrons·

After losing two electrons its electronic configuration becomes $[Ar]3d^5$· From this it is sure that this element is from the $3$d series· This $3$d series element always loses its electrons first from the $4$s orbital·

So by adding $2$ electrons to the $4$s orbital we get the ground state electronic configuration of this element·

Hence, the electronic configuration becomes $[Ar]\ 4s^2\ 3d^5$·

∴ The atomic number of X $=\ 18\ +\ 2\ +\ 5\ =\ 25$

So the element X is Manganese Mn·