This species corresponds to the 45 peak when quantifying it using IRMS. Polarization is transferred onto this species to determine its chemical identity in a technique called DEPT. This is the lighter of two species whose concentration is diluted in the Suess effect. The use of this isotope's concentration (-5[1])to detect synthetic testosterone, adulterated food, and infer prehistoric diets (15[1])comes from its different isotopic signatures in C3 and C4 (*) photosynthesis. Chemical shifts between 0 (10[1])and 220 ppm are detected in a form of NMR using this isotope, the second most-common (10[1])form after (-5[1])proton NMR. This stable isotope's natural ratio is 1.1%, and has one fewer neutron than a radioactive isotope with a half-life of 5700 years. (10[1]-5[1])For 10 points, name this isotope of Carbon that has seven neutrons. ■END■ (10[2])