Answer: c) the properties and identity of the reacting substances
Explanation: A chemical change is one in which the chemical composition of the atoms change. Every change follows law of conservation of mass and energy i.e. the mass and energy of the system remains conserved.
[tex]2H_2(g)+O_2(g)\rightarrow 2H_2O(l)[/tex]
The above equation represents a chemical change in which hydrogen and oxygen in gaseous form react to form water in liquid state. In this reaction, Oxygen is a supporter of combustion, hydrogen does not support combustion, whereas water is used to prevent combustion.
