Joseph Priestly discovered oxygen when he heated a red powder. This red powder had been prepared by heating mercury in air.
a) name th red powder formed when this element is heated in air
b) write a word equation to show what happens to this red powder when it is strongly heated in air.
I will be happy to critique your thinking on the reaction of Mercury and oxygen
a) mercury (or mercuric) oxide, HgO
b) When you strongly heat mercury oxide, it changes back to mercury (Hg) and oxygen (O2). This heating does NOT have to be done in air.