Mercury(I) fluoride

Mercury(I) fluoride, also known as mercurous fluoride, is a chemical compound. Its chemical formula is Hg2F2. It has mercury and fluoride ions in it. The mercury is in its +1 oxidation state.
Properties.
Mercury(I) fluoride is a light yellow solid. It evaporates at 240°C. It turns black when light is shined on it. It reacts with water to make mercury metal, mercury(II) oxide, and hydrofluoric acid. It is highly toxic.
Preparation.
It is made by reacting mercury(I) carbonate with hydrofluoric acid.