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05_problems - The elctronvolt (eV) is a unit of energy...

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Unformatted text preview: The elctronvolt (eV) is a unit of energy often used in particle physics. It is the kinetic energy gained by a free electron accelerated through a potential difference of 1 volt. 1eV=1.602x10-19 J 32P and 3H are common radioactive labeling elements used in biochemistry laboratories, and both undergo radioactive decay with release of a beta particle. The beta particles release by 3H and 32P have energies of 5.7 keV and 0.5 MeV, respectively. What is a beta particle? Calculate the difference in their energies for the two isotopes. Calculate their velocities using the classical equation for kinetic energy. Does anything strike you as odd about your answer? A negatively charged object A (orange) follows a trajectory that brings it close to a postively charged object B (blue). Electrostatic attraction causes A to begin to orbit about B, but frictional drag causes As velocity to decrease and it spirals in closer to B. At t2, the distance separating A and B is one half the distance at t1. How does the electrostatic potential energy of the system change between t 1 and t2? A B t1 t2 A B C D Distance between A and B Potential energy W h ic h g r a p h b e s t r e p r e s e n t s t h e c h a n g e in e n e r g y a s t h e s e p a r a t io n o f th e c h a r g e s d e c a y s o v e r t im e fo r th is s y s t e m ? Chemical cold packs used for treating injuries work by dissolving ammonium nitrate in water. The enthalpy of solution for NH4NO3 is H=25.7 kJ/mol. Is this reaction exothermic or endothermic?...
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This note was uploaded on 02/14/2012 for the course CHEM 101 taught by Professor Farahh during the Fall '02 term at UNC.

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05_problems - The elctronvolt (eV) is a unit of energy...

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