Alkali metals possess metallic lustre when freshly cut because : — s Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: Basicity of alkali metal hydroxides is determined by the ease of releasing hydroxide ions (OH-) in aqueous solution. Step 2: As we move down Group 1, the size of the metal cation increases (Li+ < Na+ < K+ < Rb+ < Cs+), increasing the M-OH bond distance and weakening the electrostatic bond strength. Step 3: Because the Cs-OH bond is the weakest and dissociates most readily to release OH- ions, basicity increases down the group in the order CsOH > RbOH > NaOH > LiOH, corresponding to option (c).