Question

Find the number of native ores out of given ores.
Pyrolusite, Chromite, Siderite, Cassiterite, Calamine, Argentite, Lime stone, Chalcopyrite

Answer 1

Native ore $\Rightarrow$ An sedimentary rock that contains a metal element in it pure state.
Pyrolusite $\to Mn{O}_2$
Chromite $\to FeC{r}_2{O}_4$
Siderite $\to FeC{O}_3$
Cassiterite $\to Sn{O}_2$
Calamine $\to ZnC{O}_3$
Argentite $\to A{g}_{2}S$
Lime stone $\to CaC{O}_3$
Chalcopyrite $\to CuFe{S}_2$