Organic molecules primarily contain carbon and hydrogen atoms. While all hydrogen isotopes are NMR-active, protium or hydrogen-1 is the most abundant and has a strong NMR absorption signal due to its large magnetogyric ratio, which causes significant energy separation between its spin states. The absorption signals of all the protium nuclei in a molecule are recorded as their chemical shifts in a proton or hydrogen-1 NMR spectrum. The proton NMR spectrum of methyl acetate shows two chemical shifts corresponding to the two types of protons in it, apart from the TMS proton signal at δ 0. The peak at δ 2.1 corresponds to the protons of the methyl groups adjacent to the carbonyl group. The downfield signal at δ 3.7 corresponds to the relatively deshielded protons of the methoxy group. Most proton chemical shifts are obtained in the narrow range of zero to ten ppm downfield from the TMS signal.