  Isobaric $^{96}_{44}$Ru+$^{96}_{44}$Ru and $^{96}_{40}$Zr+$^{96}_{40}$Zr
collisions were performed at the Relativistic Heavy Ion Collider in 2018. Using
the "a multi-phase transport" model with nuclear structures calculated by the
density functional theory (DFT), we make predictions for the charged hadron
multiplicity distributions and elliptic azimuthal anisotropies in these
collisions. Emphases are put on the relative differences between the two
collision systems that can decisively discriminate DFT nuclear distributions
from the commonly used Woods-Saxon densities.
