Final answer:
The state of matter is a physical property because it describes a substance's condition that can be observed without altering its chemical structure. Substances can transition between solid, liquid, and gas through physical changes, exemplifying physical properties that do not involve chemical transformations.
Step-by-step explanation:
Why State of Matter is a Physical Property:
The state of matter is considered a physical property because it is a characteristic of matter that can be observed and measured without changing the substance's chemical composition. Whether a substance is in the state of a solid, liquid, or gas can be changed through physical means such as heating or cooling, yet the substance's inherent chemical structure remains unaffected. Physical properties are the observable or measurable qualities of a substance that do not alter its chemical identity.
For example, water can exist as ice (solid), liquid water, or steam (gas) depending on the temperature and pressure conditions. These transformations occur without any change to the water's molecular composition of H2O, which illustrates why changes in the state of matter are categorized as physical changes. The phenomenon that a substance like water can transition between various states demonstrates its versatile physical properties, but does not affect it on a chemical level.
Moreover, according to the kinetic molecular theory, particles in different states of matter are held together by intermolecular forces and their behavior is dictated by their kinetic energy levels. This theory further supports the understanding that the state of matter is an expression of physical properties since it relates to the energy and forces among particles, rather than any change in atomic or molecular identity.