Chemical properties can only be analyzed by putting the substance through a chemical reaction, such as combustion.
Physical properties can be analyzed without altering the substance chemically. With that in mind:
Boiling point: physical
Density: physical
Ductility: physical
Heat of combustion: chemical
Explanation:
Nitric acid reacts with copper according to the reaction: ... 4 HNO3(l) + Cu(s) ==> Cu(NO3)2(s and aq) + 2 NO2(g) + 2 H2O(l) The copper nitrate salt that forms is a deep blue color. The nitrogen dioxide is a maroon vapor.
Answer:19. He says that he’s been really tired since several weeks ago. 20. A friend of us is going to pick us up at the airport. 21. I’ve worked like a waiter in the past, but I wouldn’t want to do it again. 22
Explanation:
