  The chemical composition of the Sun is a fundamental yardstick in astronomy,
relative to which essentially all cosmic objects are referenced. We reassess
the solar abundances of all 83 long-lived elements, using highly realistic
solar modelling and state-of-the-art spectroscopic analysis techniques coupled
with the best available atomic data and observations. Our new improved analysis
confirms the relatively low solar abundances of C, N, and O obtained in our
previous 3D-based studies: $\log\epsilon_{\text{C}}=8.46\pm0.04$,
$\log\epsilon_{\text{N}}=7.83\pm0.07$, and
$\log\epsilon_{\text{O}}=8.69\pm0.04$. The revised solar abundances for the
other elements also typically agree well with our previously recommended values
with just Li, F, Ne, Mg, Cl, Kr, Rb, Rh, Ba, W, Ir, and Pb differing by more
than $0.05$ dex. The here advocated present-day photospheric metal mass
fraction is only slightly higher than our previous value, mainly due to the
revised Ne abundance from Genesis solar wind measurements: $X_{\rm
surface}=0.7438\pm0.0054$, $Y_{\rm surface}=0.2423\pm 0.0054$, $Z_{\rm
surface}=0.0139\pm 0.0006$, and $Z_{\rm surface}/X_{\rm surface}=0.0187\pm
0.0009$. Overall the solar abundances agree well with those of CI chondritic
meteorites but we identify a correlation with condensation temperature such
that moderately volatile elements are enhanced by $\approx 0.04$ dex in the CI
chondrites and refractory elements possibly depleted by $\approx 0.02$ dex,
conflicting with conventional wisdom of the past half-century. Instead the
solar chemical composition resembles more closely that of the fine-grained
matrix of CM chondrites. The so-called solar modelling problem remains intact
with our revised solar abundances, suggesting shortcomings with the computed
opacities and/or treatment of mixing below the convection zone in existing
standard solar models.
