Which alloy is composed of iron, nickel, and chromium and is known for its resistance to corrosion? MCQ with Answer and Explanation

Explanation:
Froth flotation is used for sulphide ores (ZnS, PbS, CuFeS₂). Ore particles adhere to oil froth and float, gangue sinks. Magnetic separation for magnetic ores. Calcination and smelting are extraction steps, not concentration.

Explanation:
Cobalt-60 emits high-energy gamma rays used in radiotherapy (teletherapy) to treat cancers by damaging DNA of malignant cells. Carbon-14 is used for radiocarbon dating. Americium-241 is used in smoke detectors. Phosphorus-32 is used as tracer. Radiotherapy must be carefully targeted to minimize damage to healthy tissue.

Explanation:
In electrolytic refining of copper, impure copper is used as the anode, a thin sheet of pure copper as the cathode, and CuSO₄ acidified with H₂SO₄ as electrolyte. On passing current, copper dissolves from the anode and pure copper deposits on the cathode. Impurities like gold, silver fall as anode mud. This yields 99.99% pure copper. Similar process for other metals.