A mass spectrometer is used to determine the mass of the ions in a sample. Once the mass of the ions are known one can determine what molecular composition of the sample. The Behrend chemistry department has several mass spectrometers. A new singly charged ion (the sign of the charge is unknown but we know it is either teor-e) enters a velocity selector as shown with crossed electric and magnetic fields of magnitude E and 8. Only ions with the selected speed then leave through the right hole and enter a region with the same magnetic field 8 but no electric field. The magnetic force then causes the charges to move in a semi-circular path of radius as shown. By measuring & one can determine the mass of the ions. a. Is the ion positive or negative? B detector -te B b. Determine the mass of the ion in terms of e, 8, E and/orr. Show work. Note: your answer should not contain the speed v.

A mass spectrometer is used to determine the mass of the ions in a sample. Once the mass of the ions are known one can determine what molecular composition of the sample. The Behrend chemistry department has several mass spectrometers. A new singly charged ion (the sign of the charge is unknown but we know it is either teor-e) enters a velocity selector as shown with crossed electric and magnetic fields of magnitude E and 8. Only ions with the selected speed then leave through the right hole and enter a region with the same magnetic field 8 but no electric field. The magnetic force then causes the charges to move in a semi-circular path of radius as shown. By measuring & one can determine the mass of the ions. a. Is the ion positive or negative? B detector -te B b. Determine the mass of the ion in terms of e, 8, E and/orr. Show work. Note: your answer should not contain the speed v.