When mercury(II) oxide (HgO) is heated, it decomposes into its constituent elements: mercury (Hg) and oxygen (O2).

Here's the chemical equation:

2 HgO (s) → 2 Hg (l) + O2 (g)

* HgO (s): Mercury(II) oxide (solid)

* Hg (l): Mercury (liquid)

* O2 (g): Oxygen gas

Key Points:

* Decomposition reaction: This is a chemical reaction where a single reactant breaks down into two or more simpler products.

* Heat energy: Heating is necessary to provide the activation energy for the decomposition to occur.

* Observation: You would see the red-orange mercury(II) oxide solid turn into a silvery liquid mercury, and you would feel the oxygen gas being released.

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