Identify the type of reaction. 2 HgO s rightarrow 2 Hg l plus cap o sub 2 times g

Mercury(II) oxide breaks apart into mercury and oxygen: 2 HgO → 2 Hg + O₂. A reaction in which one compound splits into simpler substances is a decomposition reaction. Mercury’s oxidation state changes from +2 in HgO to 0 in Hg, so the metal is reduced, making choice D correct.

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