Daily Practice Problems

📝 SolutionMetals low in the reactivity series (like mercury, copper) can be obtained simply by heating their oxides, which decompose easily.

📝 SolutionSodium is so reactive that it catches fire in air with moisture, so it is stored under kerosene to keep it away from air and water. R correctly explains A.

📝 SolutionGraphite, an allotrope of carbon, is an exception among non-metals and conducts electricity due to free electrons.

📝 SolutionMetals tend to lose electrons to form positive ions (cations); this electropositive nature is a defining metallic property.

📝 SolutionAqua regia is a freshly prepared 3:1 mixture of concentrated hydrochloric acid and concentrated nitric acid, able to dissolve even gold and platinum.