Fundamental Properties of Matter and Kinetic Theory

Material Properties of Systems

Definitions of Matter and Systems

Matter: Anything that occupies space and has mass.
Material System: A portion of matter considered isolated for study.
Substance: A particular type of matter.

General and Specific Properties

General Properties: Properties like volume and mass that all material systems possess. They do not provide information about the type of substance.
Specific Properties: Properties that depend on the class of substance, the amount of matter, or its shape.

Mass and Volume

• Mass: A property of material systems that measures the amount of matter a body possesses.
• Volume: A property that informs how much space a material occupies. The unit in the International System is the cubic meter (m³).

Density of Bodies

Density: The mass of a substance that corresponds to a unit volume of the same. Formula: d = m / V.

Kinetic Molecular Theory

To explain the behavior of gases, physicists J. Clausius, J. Maxwell, and L. Boltzmann developed the kinetic-molecular theory in the nineteenth century.

Changes of State

• Fusion: The step of a substance from solid to liquid state. The reverse process is called freezing.
• Vaporization: The step of a substance from liquid to gaseous state, occurring in two different forms:
  • Evaporation: A slow vaporization that occurs only at the free surface of the liquid at any temperature.
  • Boiling: A tumultuous vaporization that occurs throughout the entire mass of the liquid. For a given pressure, each liquid has a characteristic boiling point (T).
• Sublimation: The direct passage from solid to gas without passing through the liquid phase. The reverse process is called regressive sublimation.

Melting and Boiling Temperatures

The temperature at which a substance melts at atmospheric pressure is called the fusion temperature, which is equal to its solidification temperature. The temperature at which a substance boils at atmospheric pressure is called the boiling temperature, which is equal to its condensation temperature.

Kinetic Theory and Temperature

The temperature of a material is proportional to the average kinetic energy of its particles.

Kinetic Theory and Pressure

Pressure: The force a gas exerts is a consequence of the collisions of its particles against the walls of the container.

State Changes According to Kinetic Theory

. D with increasing temperature a system increases the average kinetic energy and partículs d their mobility, q is the favorecn cn ls tate progressive changes: solid> liquid> gas. With increasing pressure, increase strength d ls cohesion and rewards ls regressive changes: gas> liquid> solid.