The neutrons and protons (IMAGE) University of Bonn Caption are present in the carbon nucleus as three clusters of four. Depending on the energy state of the nucleus, these can be arranged into an equilateral triangle (left) or like a slightly bent arm (right). Credit Image: Prof. Serdar Elhatisari/University of Bonn Usage Restrictions This image may be used together with the press release. License Original 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.