3rd International Clausthal chemistry workshops of Robert-Koch-school (RKS) and the Technical University of Clausthal with 24 students from L'Aigle, Oborniki Śląskie, Spišská Nová Ves, Kalyani Nagar Pune, Metzingen, Windhausen, Zorge and Clausthal-Zellerfeld,    Februar 2017