धातु कर्म (metallurgy) में, हाइड्रोजन गैस की प्रमुख भूमिका क्या होती 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