The time taken for a radioactive substance to reduce to half its initial amount is: MCQ with Answer and Explanation

Explanation:
Ca(OH)₂ + Cl₂ → CaOCl₂ + H₂O. Chlorine gas is passed over dry slaked lime. It is a mixed salt.

Explanation:
An electrolyte is a substance that produces ions when dissolved in water or melted, allowing the solution to conduct electricity. Aqueous NaCl dissociates into Na⁺ and Cl⁻ ions. Distilled water, sugar, and ethanol do not form ions in solution and are therefore non-electrolytes.

Explanation:
Rhizobium bacteria form root nodules in leguminous plants (peas, beans, clover) and fix atmospheric N₂ into ammonia, providing nitrogen to the plant, while the plant supplies carbohydrates. Azotobacter and Azospirillum are free-living nitrogen fixers. Pseudomonas is a general soil bacterium. Symbiotic association is mutualistic. Inoculating seeds with Rhizobium culture increases soil fertility.