(i)|How are metalloids different from metals? Name a metalloid.
(ii)|Differentiate between the roasting and calcination processes used in metallurgy. Give an example of each.
(i) The elements which have properties common to both metals and non-metals are metalloids whereas, metals, have unique metallic properties.
Exainples of metalloids: Boron, Silicon, Arsenic.
| Roasting | Calcination |
|---|---|
| It is a process of heating concentrated ore in | It is a process of heating concentrated ore in |
| excess air. | absence of air. |
| It is used for sulphide ore. | It is used for carbonate ore. |