Smart Toys Without the Batteries (IMAGE) American Chemical Society Caption When 'smart' puzzle pieces are pushed down into the correct spot, a letter 'C' for correct appears. Credit American Chemical Society Usage Restrictions Please credit the American Chemical Society License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.