The proton resonances of alkanes are usually found at "δ"H = 0.5–1.5. The carbon-13 resonances depend on the number of hydrogen atoms attached to the carbon: "δ"C = 8–30 (primary, methyl, –CH3), 15–55 (secondary, methylene, –CH2–), 20–60 (tertiary, methyne, C–H) and quaternary. The carbon-13 resonance of quaternary carbon atoms is characteristically weak, due to the lack of nuclear Overhauser effect and the long relaxation time, and can be missed in weak samples, or samples that have not been run for a sufficiently long time.