In a carbon-dating experiment, a particular type of mass spectrometer is used to separate 14C from 12C. Carbon ions from a sample are first accelerated through a potential difference ΔV1 between the charged accelerating plates. Then the ions enter a region of uniform vertical magnetic field B = 0.200 T. The ions pass between deflection plates spaced 1.00 cm apart. By adjusting the potential difference ΔV2 between these plates, only one of the two isotopes (12C or 14C) is allowed to pass through to the next stage of the mass spectrometer. The distance from the entrance to the ion detector is a fixed 0.200 m. By suitably adjusting ΔV1 and ΔV2, the detector counts only one type of ion, so the relative abundances can be determined.
(a) Are the ions positively or negatively charged?
(b) Which of the accelerating plates (east or west) is positively charged?
(c) Which of the deflection plates (north or south) is positively charged?
(d) Find the correct values of ΔV1 and ΔV2 in order to count 12C+ ions (mass 1.993 × 10 ˆ’26 kg).
(e) Find the correct values of ΔV1 and ΔV2 in order to count 14C + ions (mass 2.325 × 10ˆ’26 kg).

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Detector WE 0.20 m Ions Deflecting plates Accelerating plates