Final answer:
Melting and boiling points are physical properties that depend on a change of state in the material, observed during transitions from solid to liquid and liquid to gas, without changing the substance’s chemical composition.
Step-by-step explanation:
Two physical properties that depend upon a change of state in the material are melting point and boiling point. These properties are observed as a substance undergoes a transition from one state of matter to another—solid to liquid for the melting point, and liquid to gas for the boiling point.
For example, the melting point of ice is 0°C, which signifies the temperature at which it transitions from solid ice to liquid water. Similarly, water boils at 100°C, a boiling point that indicates the temperature where it transforms from a liquid to a gas (steam). These transitions do not change the chemical composition of the substance but signify a physical change in state.
Such properties are crucial because they not only help in identifying substances but also have practical applications, such as determining the purity of a material and in various industrial processes like distillation.