Which of the following metals reacts with steam but not with cold water? MCQ with Answer and Explanation

Explanation:
Green chemistry aims to design products and processes that minimize the use and generation of hazardous substances. Using hydrogen peroxide (H2O2) for bleaching paper is an example of green chemistry because it breaks down into harmless water and oxygen, unlike chlorine which can produce toxic, persistent organochlorine byproducts.

Explanation:
In electrolytic refining of copper, the electrolyte is acidified copper sulfate solution (CuSO₄ acidified with H₂SO₄). The anode is impure copper, cathode is pure copper. Cu²⁺ ions from the electrolyte are reduced and deposited on the cathode, while copper from anode oxidizes and enters solution. Impurities settle as anode mud (containing Ag, Au).

Explanation:
Cobalt-60 emits gamma rays used in radiotherapy to destroy cancerous cells. Carbon-12 and sodium-23 are stable. Phosphorus-32 is radioactive but used as tracer, not for cancer therapy.