One method for determining the amount of corn in early Native American diets is

Question

One method for determining the amount of corn in early Native American diets is the stable isotope ratio analysis (SIRA) technique. As corn photosynthesizes, it concentrates the isotope carbon-13, whereas most other plants concentrate carbon-12. Overreliance on corn consumption can then be correlated with certain diseases, because corn lacks the essential amino acid lysine. Archaeologists use the 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 8.95km/s and want to bend them within a uniform magnetic field in a semicircle of diameter 22.2cm for the 12C. The measured masses of these isotopes are 1.99

Explanation / Answer

a)

B = m*v/r*q = 1.99*10^-26*8.95*10^3/(22.2*10^-2/2)*1.6*10^-19 = 0.01 T

b)

r' = m'*v/q*B = 2.16*10^-26 * 8.95*10^3/1.6*10^-19*0.01 = 0.1208

D = 2*r' = 2*0.1208 = 0.2416 m = 24.16 cm

c)

0.2416 - 0.222 = 0.0196 m = 1.96 cm

Related Questions

Navigate

• Browse (All)
• Browse O
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.