Q1. The most commonly used chemical for artificial rain or cloud seeding is:
A Ferrous sulphate
B Silver iodide Correct
C Copper sulphate
D Potassium nitrate
Explanation
Silver iodide is widely used in cloud seeding because its crystal structure helps water vapour form ice crystals in suitable clouds, encouraging precipitation. Ferrous sulphate and copper sulphate are common salts with other industrial or laboratory uses, but they are not the standard seeding agents for artificial rain. Potassium nitrate is an oxidising salt used in areas such as fertilisers and pyrotechnics; it does not serve the usual ice-nucleating role required in cloud seeding.