Glass is considered a: MCQ with Answer and Explanation

Explanation:
Limestone is CaCO₃. On strong heating, it decomposes to calcium oxide (quicklime) and carbon dioxide: CaCO₃ → CaO + CO₂. This is a decomposition reaction used in cement and lime manufacturing. CaO is used in building and as a drying agent.

Explanation:
Enzymes exhibit substrate specificity, meaning each enzyme catalyzes a particular reaction or acts on a specific substrate (lock-and-key model). For example, urease acts only on urea. This specificity is due to the unique shape of the active site. Denaturation is loss of structure, inhibition is blocking activity, optimum temperature is condition for maximum activity.

Explanation:
Catalytic converters use precious metals like platinum, palladium, and rhodium as catalysts to convert toxic exhaust gases (CO, NOx, unburnt hydrocarbons) into less harmful substances (CO₂, N₂, H₂O) before they are released into the atmosphere. These metals are chosen for their high catalytic activity and durability.