  The anisotropy coefficient $v_2$, for unidentified and identified charged
hadrons [pions ($\pi$), kaons ($K$) and protons ($p$)] measured in Au+Au
collisions at $\sqrt{s_{NN}}= 0.20$ TeV (RHIC) and Pb+Pb collisions at
$\sqrt{s_{NN}}= 2.76$ TeV (LHC), are compared for several collision
centralities ($\text{cent}$) and particle transverse momenta $p_T$. In contrast
to the measurements for charged hadrons, the comparisons indicate a sizable
increase of $v_2(p_T)$ for $\pi,K$ and $p$, as well as a blueshift of proton
$v_2(p_T)$, from RHIC to LHC. When this blueshift is accounted for, the LHC
data [for $\pi$, $K$, $p$] show excellent scaling of $v_2({KE}_T)$ with the
number of valence quarks ($n_q$), for a broad range of transverse kinetic
energies (${KE}_T$) and collision centralities. These observations suggest a
larger mean sound speed $<c_s(T)>$ for the plasma created in LHC collisions,
and significant radial flow generation after its hadronization.
