Chapter 1 (Lesson 2)

Vocabulary flashcards covering key terms from Chapter One: Matter, Measurement, and Problem Solving, focusing on physical and chemical changes/properties and energy concepts.

Matter

Anything that has mass and occupies space.

Physical Change

A change that alters only the state or appearance of a substance; no new substance is formed and the substance's identity remains the same.

Chemical Change

A change that alters the chemical identity or composition of a substance; a new substance with different properties is formed.

Physical Property

A characteristic observed without changing the substance's composition (e.g., odor, color, density, melting/boiling points).

Chemical Property

A characteristic observed only through a chemical change that involves altering a substance's composition (e.g., flammability, reactivity, acidity, toxicity, corrosiveness).

Boiling

A physical process where a liquid becomes a gas when its vapor pressure reaches the surrounding pressure; the substance remains the same chemically.

Vaporization

General term for the phase change from liquid to gas; includes boiling and evaporation.

Rusting

A chemical change in which iron reacts with oxygen to form iron oxide (Fe2O3); a new substance is produced.

Iron Oxide (Fe2O3)

The chemical compound formed when iron oxidizes; commonly known as rust.

Gasoline

A liquid hydrocarbon fuel that stores chemical energy and burns to release energy.

Odor

A physical property describing a substance’s smell, observed without changing its composition.

Taste

A physical property describing a substance’s flavor, observed without changing its composition.

Color

A physical property describing how a substance appears to the eye, based on light absorption/reflection.

Appearance

A physical property describing the external look or visible characteristics of a substance.

Melting Point

The temperature at which a solid changes into a liquid.

Boiling Point

The temperature at which a liquid changes into a gas.

Density

Mass per unit volume; a physical property.

Flammability

A chemical property describing how readily a substance burns in the presence of an oxidizer.

Corrosiveness

A chemical property describing the ability of a substance to wear away other materials through chemical reaction.

Acidity

A chemical property describing how likely a substance is to donate protons (acid behavior).

Reactivity

A chemical property describing how readily a substance undergoes chemical reactions.

Toxicity

A chemical property describing harmful effects on health.

Energy

The capacity to do work or cause change; present in all physical and chemical processes.

Kinetic Energy

Energy of motion; depends on the mass and velocity of an object.

Potential Energy

Energy stored due to position or configuration.

Mechanical Energy

Energy associated with an object's motion and/or position (sum of kinetic and potential energy).

Thermal Energy

Energy related to the temperature of a system, arising from molecular motion.

Chemical Energy

Energy stored in chemical bonds that can be released or absorbed during chemical reactions.

Law of Conservation of Energy

Energy is neither created nor destroyed in a closed system; it is conserved and can be transformed from one form to another.

Combustion

A chemical reaction that typically releases energy by reacting a fuel with an oxidizer (usually oxygen).

Photosynthesis

The process by which plants convert light energy into chemical energy stored in glucose, using CO2 and H2O.

Energy Transformation

The conversion of energy from one form to another (e.g., chemical energy to mechanical energy).