Kaplan Nursing Entrance Exam Practice 2025 – Comprehensive Prep

Melting and boiling points are classified as physical properties because they describe the phase transitions of a substance without altering its chemical composition. When a substance melts, it changes from a solid to a liquid, and when it boils, it transitions from a liquid to a gas. These changes are related to the energy of the molecules and the intermolecular forces acting on them but do not involve any change in the chemical identity of the substance.

In contrast, chemical properties would include characteristics that determine how a substance reacts with other substances, such as acidity or flammability. Reactivity properties are a subset of chemical properties that specifically pertain to how a substance may undergo reactions. Solubility properties refer to how well a substance can dissolve in another substance, which is also distinct from melting and boiling points. Therefore, classifying melting and boiling points as physical properties is the most accurate representation of their nature.