Metals found in free as well as combined states are
Gold and Silver
Gold and silver occurs in free as well as in combined states in nature.
Auto-reduction process is used in the extraction of
Among the following groups of oxides, the group containing oxides that cannot be reduced by carbon to give the respective metal is
van-Arkel method of purification of metals involves converting the metal to a
A metal which is refined by poling is
Wolframite ore is separate from tin stone ore by the process of
Pb and Sn are extracted from their chief ore by
‘Lapis-Lazuli’ is a blue coloured precious stone. It is mineral of the class
Gallium arsenide is purified by
Which of the following is correct?
By which of the following processes, the ore is made porous?