Physical Properties and Changes of Matter

Study Notes

Physical Properties

Matter exists in three fundamental states: solid, liquid, and gas. These states differ in the arrangement and movement of their constituent particles.
Solids have a definite shape and volume due to tightly packed particles with strong intermolecular forces.
Liquids have a definite volume but take the shape of their container. Particles are close together but can move past each other.
Gases have neither a definite shape nor a definite volume. Particles are widely spaced and move freely in all directions.

Physical Changes

A physical change alters the form or appearance of a substance, but does not change its chemical composition. Examples include melting, freezing, boiling, condensing, and sublimation.
These changes involve rearrangements of particles but do not break or form new chemical bonds.
Physical changes are often reversible, meaning the original substance can be recovered by reversing the change.

Physical Properties of Substances

Density is the mass per unit volume of a substance. High density indicates a tightly packed arrangement of particles.
Melting point is the temperature at which a solid changes its state to a liquid.
Boiling point is the temperature at which a liquid changes its state to a gas.
Solubility refers to the ability of one substance to dissolve in another.
Electrical conductivity is the ability of a substance to conduct an electric current.
Thermal conductivity is the ability of a substance to conduct heat.
Malleability is the ability of a substance to be hammered or rolled into thin sheets.
Ductility is the ability of a substance to be drawn into wires.
Hardness is the resistance of a substance to scratching or indentation.
Magnetism describes the ability of a substance to attract iron or other magnetic materials.
Color is a visual property associated with the wavelengths of light reflected or absorbed by a substance.
Odor is the smell associated with a substance. Smells can vary considerably from substance to substance.
Texture describes the surface feel of a substance. This is a sensory qualitative observation.

Measurement of Physical Properties

Accurate measurement of physical properties is critical to characterizing substances.
Tools and techniques vary depending on the property being measured. Measuring tools are necessary to observe and understand these properties.
Common instruments include thermometers, balances, graduated cylinders, and spectrometers.
Precise measurements are fundamental for scientific inquiry.

Relationship Between Structure and Properties

The arrangement and type of particles within a substance influence its physical properties.
For example, the strong forces between particles in a solid result in a fixed shape and volume, whereas the weaker forces between particles in a gas allow them to move freely.
Molecular structure dramatically impacts the observable physical properties.

Description

Explore the fundamental states of matter and their physical properties, including solids, liquids, and gases. This quiz also covers physical changes such as melting and boiling, highlighting how these changes affect substances without altering their chemical composition. Test your understanding of these key concepts in science.