Half-life of a radioactive isotope is 5 years. What percentage remains after 15 years? MCQ with Answer and Explanation

Explanation:
V ∝ T (in Kelvin). Using Celsius gives a linear relationship but not direct proportionality (line does not pass through origin). Absolute zero (0 K = -273.15°C) is the theoretical temperature of zero volume.

Explanation:
Vulcanization is the process of heating natural rubber with sulphur (usually at 100-140°C) to improve its properties. Sulphur forms cross-links (disulfide bridges) between the polymer chains, making the rubber harder, more elastic, and less sensitive to temperature changes.

Explanation:
UV radiation releases chlorine atoms from CFCs; Cl catalytically decomposes O₃: Cl + O₃ → ClO + O₂; ClO + O → Cl + O₂. One Cl atom can destroy thousands of ozone molecules.