Methane is the first member of the alkane series. Its molecular formula is: MCQ with Answer and Explanation

Explanation:
Rutherford bombarded a thin gold foil with alpha particles. Most passed through, but some were deflected, leading to the nuclear model.

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.

Explanation:
Rusting is a chemical change because iron reacts with atmospheric oxygen and moisture to form hydrated iron(III) oxide. This new compound possesses entirely different chemical properties from the original iron. The process involves the formation of new chemical bonds and cannot be easily reversed by simple physical methods.