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.

29.1-12=17.1the answer is this one

Determine the  wavelength of light emitted when an electron  in an li2+ ion  makes a transition from an orbital with n  =  6 to an orbital with n  = 5.