(i) (a)
| Slag |
Flux |
| It is the product obtained by the combination of the flux with gangue in metallurgy. |
It is a substance which is added along with charge to separate the gangue in metallurgy. |
(b)
| Calcination |
Roasting |
| It is the process of heating concentrated ore in a limited supply of air to a temperature insufficient to melt the ore. |
It is the process of heating concentrated ore in a free supply of air to a temperature insufficient to melt the ore |
| During calcination, no other chemical change occurs except decomposition. |
During roasting, chemical changes like oxidation or reduction take place. |
(ii) (a) Metals complete their octet by the loss of electrons whereas non-metals complete their octet by the gain of electrons. Metals generally contain 1 to 3 valence electrons in their outermost shell whereas non-metals contain 4 to 7 valence electrons in their outermost shell.
(b) Metals form basic oxides whereas non-metals form acidic oxides.
(c) Metals are reducing agents whereas non-metals act as oxidising agents.
(d) Metals He generally good conductors of heat and electricity whereas non-metals are bad conductors of heat and electricity.
(iii) (a) The minerals contain a low percentage of metal, while the ores contain a large percentage of the metal.
(b) The metal cannot be extracted from mineral, on the other hand ores can be used for the extraction of metal.
(c) All minerals are not ores, but all ores are minerals.
