The diagram shows a mass spectrometer used for measuring the masses of isotopes. It consists of an ion generator and accelerator, a velocity selector and an ion separator, all in a vacuum. In one experiment, tin ions, each of which carries a charge +1.6 × 10-19C, are produced in the ion generator and are then accelerated by a p.d. of 20kV. Tin has a number of isotopes, two of which are tin-118 (118Sn) and tin-120 (120Sn). (a.) After selection, the ions are separated using a magnetic field on its own, as shown in the diagram. The ions are detected using the photographic plate P. Determine the distance between the points of impact on the photographic plate of the two isotopes of tin when a magnetic flux density of 0.75T is used in the ion separator. Explain whether the distance between the points of impact of the ions would be the same, greater or smaller for two isotopes of uranium, one with a nucleon number of 236 and the other 238, assuming that they have the same velocity as the tin ions.

The diagram shows a mass spectrometer used for measuring the masses of isotopes. It consists of an ion generator and accelerator, a velocity selector and an ion separator, all in a vacuum. In one experiment, tin ions, each of which carries a charge +1.6 × 10-19C, are produced in the ion generator and are then accelerated by a p.d. of 20kV. Tin has a number of isotopes, two of which are tin-118 (118Sn) and tin-120 (120Sn). (a.) After selection, the ions are separated using a magnetic field on its own, as shown in the diagram. The ions are detected using the photographic plate P. Determine the distance between the points of impact on the photographic plate of the two isotopes of tin when a magnetic flux density of 0.75T is used in the ion separator. Explain whether the distance between the points of impact of the ions would be the same, greater or smaller for two isotopes of uranium, one with a nucleon number of 236 and the other 238, assuming that they have the same velocity as the tin ions.