Question

The following properties are either physical or chemical. Which one is different from the rest based on those two categories?

Answer 1

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

Answer 2

Hello :)

They are simply asking us to find which one of these properties are different from the rest, so we need to categorize them.

Boiling point , would belongs in the physical change category

Density , Also belongs in the physical change category.

Ductility , Also belongs in the physical change category.

Heat of combustion, Belongs in the chemical change category. Since this is the only property that is different from the rest / in a different category, this would be the answer.

So, the answer would be D. Heat of Combustion