Predicted elemental abundances of the Jovian (left) and Saturnian (right) atmospheres normalized by the protosolar value. We have evaluated atmospheric elemental abundances using the volatile abundances at 5 AU for Jupiter and 10 AU for Saturn. The empty dots denote the abundances constrained by the Galileo probe, Cassini, and JUNO observations from Atreya et al. (2020). The observational abundances are normalized by the protosolar abundances of Asplund et al. (2021), and we also plot the abundances normalized by the protosolar abundances of Lodders et al. (2009) for P and Ar, where (A) and (L) indicate Asplund et al. (2021) and Lodders et al. (2009), respectively. The empty green dot denotes the oxygen abundance at the deep equatorial region of Jupiter retrieved by JUNO (Li et al. 2020). We caution that the observed P abundances may not represent the bulk abundances, that the N abundance in Saturn may be a lower limit, and that the S abundance in Saturn is model dependent (see Atreya et al. 2018).