The melting point of table salt is 801℃. is this a physical or chemical property?

Well you are changing its appearence so some would say physical but i think its chemical 

Because electrons have negligible mass, to account for the mass of the isotope, there must be 16 neutrons, 16 neutrally charged, massive, fundamental particles present in the sulfur nucleus. and thus finally, if we have the 32s2− ion, there are 18 electrons, 16 protons, and 16 neutrons.