Chemical element same atomic number, or number of protons. Nuclear scientists, however, define a pure element as one that consists of only one stable isotope. For example, a copper wire is 99.99% chemically pure if 99.99% of its atoms are copper, with 29 protons each. However it is not isotopically pure since ordinary copper consists of two stable isotopes, 69% Cu and 31% Cu, with different numbers of neutrons. However, a pure gold ingot would be both chemically and isotopically pure, since ordinary gold consists only of one isotope, Au. Atoms of chemically pure elements may bond to each other chemically in
CU Spaceflight offer to do so, hoping to raise the profile of engineering and aerospace in particular. During the 2007 Cambridge Science Festival, CU Spaceflight launched their Nova 5 balloon in front of a large crowd. CU Spaceflight CU Spaceflight is a student-run Cambridge University society founded with the aim of achieving cheap access to space. It is supported by the Cambridge-MIT Institute. The project was founded in the summer of 2006, with the specific goal of launching a rocket into space for less than GBP£1000. As of November, 2007, CU Spaceflight has launched five uncrewed high-altitude balloons, of which two were