Question

Why manganese dioxide is written as Mno2 .Prove it

Answer 1

Valency of manganese is 2
Valency of dioxide is also 2
By cross multiplication of Valencies we get Mno2

Answer 2

Answer: Because manganese has an oxidation state of +4.

Explanation:

Manganese is the 25th element of the periodic table. The electronic configuration of this element is :$[Ar]4s^23d^5$. The most common oxidation states of this element are +2, +3, +4, +6 and +7.

Oxygen is the 8th element of the periodic table and the electronic configuration of this element is : $[He]2s^22p^4$. The most common oxidation state of this element is -2.

To form manganese dioxide, manganese will form the compound having +4 oxidation state, so that it can form $MnO_2$

By Criss-cross method, we can easily write the chemical formula of manganese dioxide.