  We assess the impact of the trace element Ne-22 on the cooling and seismology
of a liquid C/O white dwarf (WD). Due to this element's neutron excess, it
sinks towards the interior as the liquid WD cools. The gravitational energy
released slows the WD's cooling by 0.5-1.6 Gyr. In addition the Ne-22 abundance
gradient changes the periods of the high radial order g-modes at the 1% level.
