Why does calcium start floating when it reacts with water? Write the balanced chemical equation of the reaction. (b) Name two metals which do not react with water. a) Ca + 2H₂O → Ca(OH)₂ + H₂; Gold and Platinum b) Ca + 2H₂O → Ca(OH)₂ + H₂; Silver and Copper c) Ca + 2H₂O → Ca(OH)₂ + H₂; Gold and Silver d) Ca + 2H₂O → Ca(OH)₂ + H₂; Platinum and Copper