Why is melting a physical property of the wax, but flammability is a chemical property?

Melting is a physical property and a physical change to wax. We know this because although the wax might melt, it will resolidify into its original form. Flammability, however, is a chemical change because the act of burning involves a chemical reaction between the gases in the air and heat, which cannot be reversed.

They are like other investigations? say there was a murder u have to do blood test and finger prints which run through a lab. 

257 grams h2o i think