Alpha particle types: eventually named alpha, beta, and gamma by Rutherford, based on penetration of objects and deflection by a magnetic field. Alpha rays were defined by Rutherford as those having the lowest penetration of ordinary objects. Rutherford's work also included measurements of the ratio of an alpha particle's mass to its charge, which led him to the hypothesis that alpha particles were doubly charged helium ions (later shown to be bare helium nuclei). In 1907, Ernest Rutherford and Thomas Royds finally proved that alpha particles were indeed helium ions. To do this they allowed alpha particles to penetrate a very thin
Nitrogen-15 nuclear magnetic resonance spectroscopy Nitrogen-15 nuclear magnetic resonance spectroscopy Nitrogen-15 nuclear magnetic resonance spectroscopy (nitrogen-15 NMR spectroscopy, or just simply N NMR) is a version of nuclear magnetic resonance spectroscopy that examines samples containing the N nucleus. N NMR differs in several ways from the more common C and H NMR. To lift the restraint of spin 1 found in N, N NMR is employed in samples for detection since it has a ground-state spin of ½. SinceN is 99.64% abundant, incorporation of N into samples often requires novel synthetic techniques. Two sources of nitrogen-15 are the positron emission of oxygen-15 and the beta