  Recently, phonons with chirality (chiral phonons) have attracted significant
attention. Chiral phonons exhibit angular and pseudo-angular momenta. In
circularly polarized Raman spectroscopy, the peak split of the $\Gamma_3$ mode
is detectable along the principal axis of the chiral crystal in the
backscattering configuration. In addition, peak splitting occurs when the
pseudo-angular momenta of the incident and scattered circularly polarized light
are reversed. Until now, chiral phonons in binary crystals have been observed,
whereas those in unary crystals have not been observed. Here, we observe chiral
phonons in a chiral unary crystal Te. The pseudo-angular momentum of the phonon
is obtained in Te by an $\textit{ab initio}$ calculation. From this
calculation, we verified the conservation law of pseudo-angular momentum in
Raman scattering. From this conservation law, we determined the handedness of
the chiral crystals. We also evaluated the true chirality of the phonons using
a measure with symmetry similar to that of an electric toroidal monopole.
