The ionic mobility of alkali metal cations in an aqueous solution under an applied electric field fo — s Block Elements Chemistry Question

💡 Solution & Explanation

Ionic mobility in aqueous solution is inversely proportional to the hydrated radius. Because the small $Li^+$ ion has the highest charge density, it is the most heavily hydrated and has the largest hydrated radius, making it move the slowest. $Cs^+$ is the least hydrated and moves the fastest.