BiI3 with triiodide (I3^-) ion never exists. — p Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: Cyclic (or ring) silicates are formed by sharing two oxygen atoms per tetrahedral SiO4^4- unit. Step 2: The sharing of two oxygen atoms reduces the formula of each unit to SiO3^2-. When these units link in a ring (such as Si3O9^6- or Si6O18^12-), the overall stoichiometry remains (SiO3^2-)_n. Step 3: Therefore, the repeating silicate ion composition that constructs a cyclic skeleton is SiO3^2-, matching option (c).