Determining Diet One method for determining the amount of com in early Native American diets is the stable isotope ratio analysis (SIRA) technique. As com photosynthesizes, it concentrates the isotope carbon-l3. Where as most other plants concentrate carbon-12. Over reliance on com consumption can then he correlated with certain diseases, because com lacks the essential amino acid lysine. Archaeologists use a mass spectrometer to separate the 12C and 13C isotopes in samples of human remains. Suppose you use a velocity selector to obtain singly ionized (missing one electron) atoms of speed 8.50 km/s, and you want to bend them within a uniform magnetic field in a semicircle of diameter
25.0 cm for the 12C The measured masses of these isotopes are 1.99 X 10-26 kg (12C) and 2.16 X 10-26 kg (I3C).
(a) What strength of magnetic field is required?
(b) What is the diameter of the I3C semicircle?
(c) What is the separation of the 12C and 13C ions at the detector at the end of the semicircle? Is this distance large enough to be easily observed?