. . Extracting Metals Low in the Activity Series Metals low in the activity series are very unreactive. The oxides of these metals can be reduced to metals by heating alone.
For example, cinnabar (HgS) is an ore of mercury. When it is heated in air, it is first converted into mercuric oxide (HgO). Mercuric oxide is then reduced to mercury on further heating. 2HgS(s) + 3O (g) 2HgO(s) + 2SO (g) Heat 2HgO(s) 2Hg(l) + O (g) Heat Similarly, copper which is found as Cu S in nature can be obtained from its ore by just heating in air.
2Cu S + 3O (g) 2Cu O(s) + 2SO (g) 2Cu O + Cu S Heat Heat 6Cu(s) + SO (g)