Modern periodic law states that properties of elements are periodic functions of their: MCQ with Answer and Explanation

Explanation:
Graham's law of effusion/diffusion: Rate ∝ 1/√M (molar mass) at same temperature and pressure. Lighter gases diffuse faster. This is used in isotope separation (e.g., ²³⁵UF₆ vs ²³⁸UF₆) and in understanding gas behavior in leaks.

Explanation:
Niels Bohr proposed his model in 1913 to overcome the defects of Rutherford's model. He stated that electrons revolve around the nucleus in specific, discrete circular orbits (shells) with fixed energy, and they do not radiate energy while in these orbits, explaining atomic stability.

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.