Is melting of gold a physical property?
It is a phase change - gold exists as a solid crystal (fcc I believe off the top of my head), as a liquid, and as a vapor (gas).  First order phase transitions exhibit a volume change, and an enthalpy of the phase change.  In the case of gold, both the crystal and the liquid are metallic, with similar numbers of nearest neighbors. 

All elements exhibit various phases.  Since pure gold is, well, pure gold, I'm not sure how a phase change in gold could be considered a 'chemical change', particularly in the solid-to-liquid.  The type of bonding does not change, and there are no 'chemical reactions' going on. This is all fairly basic thermodynamics.