Which of the following reactions is a combination reaction?
A. NaCl + AgNO₃ → AgCl + NaNO₃
B. 2Mg + O₂ → 2MgO
C. CaCO₃ → CaO + CO₂
D. Zn + CuSO₄ → ZnSO₄ + Cu
Answer: Option B
Solution (By JKExamLibrary)
Combination: two or more reactants combine to one product. Mg and O₂ combine to form MgO. A is decomposition; B is displacement; D is double displacement.
Explanation:
Cinnabar is HgS, the chief ore of mercury. Bauxite (Al), galena (Pb), magnetite (Fe). Mercury is extracted by roasting cinnabar in air: HgS + O₂ → Hg + SO₂.
Explanation:
Iodine-131 is a radioactive isotope used to treat thyroid disorders including goitre and cancer. Carbon-14 for dating, Cobalt-60 for cancer therapy, Uranium-235 as fuel in nuclear reactors. Non-radioactive isotopes are used as tracers. Goitre is often caused by iodine deficiency, but radioactive iodine can be used therapeutically.
Explanation:
Cobalt-60 is a gamma-ray emitter used in radiotherapy to destroy cancerous cells. Iodine-131 is used for thyroid cancer and disorders. Carbon-14 is used in radiocarbon dating. Uranium-235 is used as fuel in nuclear reactors and weapons. Radioisotopes for medical use are produced in nuclear reactors. Gamma rays penetrate and damage DNA of rapidly dividing cells.
No comments yet. Be the first to start the discussion!