Chemistry: Matter, Properties, and Change

Vocabulary flashcards covering the fundamental concepts of chemistry, including the properties of matter, classification of substances and mixtures, chemical analysis techniques, states of matter, and types of changes.

Chemistry

The branch of science that studies matter—its composition, structure, properties, and the changes it undergoes.

Properties

Characteristics or qualities of a substance that can be observed or measured and that help describe or identify it.

Physical Properties

Properties that can be observed or measured without changing the identity of the substance.

Intensive Physical Properties

Properties that do not depend on the amount of matter present, such as density, color, boiling point ($100\,^\circ\text{C}$ for water), and melting point ($0\,^\circ\text{C}$ for ice).

Extensive Physical Properties

Properties that depend on the amount of matter present, such as mass, volume, length, and amount of energy.

Chemical Properties

Properties that describe a substance’s ability to undergo a chemical change and form a new substance, such as flammability and toxicity.

Oxidation tendency

The ability of a substance to combine with oxygen, such as copper turning green (patina) when exposed to air.

Combustibility

How easily a substance can catch fire and continue burning.

Reactivity with water

How a substance reacts when mixed with water, such as sodium reacting violently to produce hydrogen gas.

Stability

A measure of how easily a substance breaks down or reacts.

Composition

The kinds and amounts of substances or elements that make up a material.

Pure Substances

Types of matter that have a fixed (definite) composition and uniform properties throughout, and cannot be separated by physical methods.

Elements

Pure substances made of one kind of atom, such as Oxygen ($O_2$), Iron ($Fe$), and Gold ($Au$).

Compounds

Pure substances made of two or more elements chemically combined, such as Water ($H_2O$), Carbon dioxide ($CO_2$), and Salt ($NaCl$).

Mixtures

A type of matter made when two or more substances are physically combined but are not chemically bonded.

Homogeneous mixture

A mixture that is uniform throughout and looks the same, also known as a solution (e.g., air, salt water, vinegar).

Heterogeneous mixture

A mixture with a non-uniform composition where different parts or layers can be seen (e.g., sand and water, salad).

Decomposition Reactions

Chemical reactions used to break down substances that cannot be separated physically, such as the electrolysis of water into hydrogen and oxygen.

Spectroscopy

An instrumental method that identifies elements based on light absorption or emission.

Mass spectrometry

An advanced tool used to determine atomic or molecular composition.

Chromatography

A method used to separate and identify components in mixtures.

Structure

The arrangement and organization of particles (atoms, molecules, or ions) in a substance and how they are connected or packed together.

Solid

A state of matter where particles are tightly packed and fixed in place, resulting in a fixed shape and volume.

Liquid

A state of matter where particles are close but can move or slide past each other, taking the shape of the container.

Gas

A state of matter where particles are far apart and move freely, expanding to fill any space.

Physical Change

A change in the size, shape, or state of matter without changing its chemical composition, such as melting ice or tearing paper.

Chemical Change

A change in which one or more new substances with different properties are formed, such as rusting iron or burning wood.

Precipitate

A solid that forms during a chemical change.