Which of the following compounds is electron-deficient? MCQ with Answer and Explanation

Explanation:
Distilled water is produced by boiling water and condensing the steam, leaving behind non-volatile impurities like salts, minerals, and most contaminants. It is almost pure H₂O. Deionized water also has salts removed. However, it may absorb CO₂ and become slightly acidic. It is used in laboratories and batteries.

Explanation:
Contact process: Sulfur or pyrite (FeS₂) is burned in air to form SO₂, then SO₂ is oxidized with O₂ over V₂O₅ catalyst to SO₃, which is absorbed in concentrated H₂SO₄ to produce oleum, then diluted to get H₂SO₄. Raw materials: sulfur (or pyrite), air, and water (for dilution). Not NaCl or NH₃.

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.