Terylene is also known as: MCQ with Answer and Explanation

Explanation:
Hydrogenation of alkenes (addition of H₂ across double bond) is catalyzed by finely divided metals like nickel, platinum, or palladium. These adsorb H₂ and the unsaturated compound, facilitating reaction. V₂O₅ is for oxidation (Contact), MnO₂ for H₂O₂ decomposition, Fe for Haber process. Nickel is the most common industrial catalyst for hydrogenation.

Explanation:
Down a group, number of shells increases, atomic radius increases, and inner electrons shield the outermost electron from the nucleus. The effective nuclear charge experienced by valence electron decreases, making it easier to remove. Thus ionization energy decreases. For example, IE of Cs

Explanation:
Evaporation of water is a physical change—liquid water changes to water vapor, but the chemical composition (H₂O) remains unchanged. Souring of milk and curd formation involve lactic acid bacteria converting lactose to lactic acid (chemical change). Fermentation of grapes involves yeast converting sugars to ethanol and CO₂. Chemical changes produce new substances. Physical changes only alter the state or form.