Answer: freezing point
Step-by-step explanation:
Chemical property is defined as the property of a substance which is observed during a reaction where the chemical composition identity of the substance gets changed.
Physical property is defined as the property which can be measured and whose value describes the state of physical system. For Example: State, density etc.
Flammability is a chemical property as it alters the chemical composition of substance.
pH is a chemical property as it alters the chemical composition of substance.
Toxicity is a chemical property as it alters the chemical composition of substance.
Freezing point is a physical property as it deals only with phase changes.