सल्फाइड अयस्कों का सांद्रण आमतौर पर निम्नलिखित में से किस विधि द्वारा किया जाता है?

The amalgamation process is primarily used to extract which of the following metals?

The crude iron directly obtained from the reduction of iron ore in a blast furnace is known as:

Match List-I (Metal) with List-II (Refining Process) and select the correct answer using the codes given below: List-I: a) Ni, b) Cu, c) Zr, d) Ge List-II: 1) Van Arkel process, 2) Electrolysis, 3) Mond process, 4) Zone refining