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 to detect synthetic testosterone, adulterated food, and infer prehistoric diets comes from its different isotopic signatures (-5[1])in C3 and C4 (*) photosynthesis. Chemical shifts between 0 and 220 ppm are detected in a form of NMR using this isotope, the second (10[1])most-common form after proton NMR. This stable isotope's natural ratio is 1.1%, (10[1])and has one fewer neutron than a radioactive isotope (-5[1])with a half-life of 5700 years. (10[1])For 10 points, name this isotope of Carbon that has seven neutrons. ■END■ (10[2])