Lithium does not form solid hydrogen carbonate. Lithium forms only the normal carbonate, Li2CO3. It does not form any basic carbonate having both carbonate and hydroxide ions. Li differs from the rest of the family members and shows anomalous behaviour. Lithium bicarbonate is found in solution form while bicarbonates of other alkali metals exist in solid state. Its anomalous behaviour isdue to the following reasons: 1. Its exceptionally small size; and 2. High polarising power