Manganese IV oxide has the chemical formula MnO2. Manganese in this compound has an oxidation state of +4. The electronic configuration of manganese is [Ar] 3d5 4s2. When it forms MnO2, it loses 4 electrons, resulting in an electronic configuration of [Ar] 3d3.MnO2 is a transition metal oxide, and the color of transition metal compounds is often due to the presence of unpaired d-electrons. In the case of MnO2, there are three unpaired electrons in the 3d orbitals. These unpaired electrons can undergo d-d transitions, which involve the absorption of light in the visible region of the electromagnetic spectrum. The absorbed light corresponds to a specific wavelength, and the complementary color of that wavelength is what we perceive as the color of the compound.Manganese IV oxide, MnO2, is known to be a black or dark brown solid. The presence of unpaired electrons in the 3d orbitals and the d-d transitions contribute to this color.