Chemistry MCQs

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Bananas contain potassium-40, a radioactive isotope of potassium, which makes them slightly radioactive. The radiation is very minor and not dangerous at all to humans, but it is enough to trigger sensitive radiation sensors. The potassium provides bananas some of their nutritional benefits as well.

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Radium(Ra) with atomic number 88 was discovered by Marie and Pierre Curie in 1898 as Radium Chloride. However, it was Radium was isolated in its metallic state by Marie Curie and André-Louis Debierne through the electrolysis of radium chloride in 1911.

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Gobar Gas or Biogas is mostly methane (CH₄) and carbon dioxide (CO₂) and may have small amounts of hydrogen sulfide (H₂S), moisture and siloxanes.

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Galena and litharge are ores of lead. Galena is the most common ore of lead. It is the natural mineral form of lead (II) sulphid. Litharge is a secondary mineral that forms from the oxidation of galena ores. It is one of the natural mineral forms of Lead(II) oxide.

Notes:
The correct answer is Helium. Helium is a non-flammable, lighter-than-air gas, making it safe for use in balloons. Unlike hydrogen, which is highly flammable and poses explosion risks, helium is inert and does not react with other substances. Helium is the second most abundant element in the universe, primarily produced through nuclear fusion in stars. It was first discovered in the sun before being found on Earth.

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Vulcanization introduces sulfur cross-links between poly-isoprene chains in natural rubber, restricting movement, which increases stiffness, elasticity, and durability. This chemical modification prevents rubber from becoming sticky or brittle, significantly improving its mechanical properties for industrial and commercial use.

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Acid rain, or acid deposition, is a broad term that includes any form of precipitation with acidic components, such as sulphuric or nitric acid that fall to the ground from the atmosphere in wet or dry forms.

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“Butter of Tin” is also known as tin tetrachloride pentahydrate. It is called “butter of tin” because of its physical appearance. Its chemical formula is SnCl4*5H2O or [SnCl4 (H2O)]*3H2O.

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Due to the relatively smaller size of particles, as compared to that of a suspension, the mixture appears to be homogeneous. But actually, a colloidal solution is a heterogeneous mixture. The particles can easily scatter a beam of visible light.

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Gypsum is a mineral composed of calcium sulfate dihydrate. It’s a soft mineral and colorless to white in color. It is commonly added to saline soils to reduce salinity and also used in wallboard (drywall) and plaster of paris.