Chapter 1 – Measurement and the Properties of Matter

Vocabulary flashcards covering fundamental chemistry definitions, scientific method principles, classification of matter, properties, measurement units, and precision metrics from Chapter 1.

Chemistry

The study of matter and the changes it undergoes.

Matter

Anything that has mass and occupies space.

Atom

A tiny particle that composes matter.

Scientific Method

The process of observing and understanding the natural world by discovering connections between phenomena through careful application of experience and reason.

Observation

The data-gathering process within the scientific method.

Measurement

A quantitative, numerical observation.

Hypothesis

A reasonable, but tentative, explanation or educated guess for a set of observations.

Experiment

An observation designed and controlled by humans, often performed in a laboratory, to test a hypothesis.

Theory

A well-confirmed framework of ideas (unifying principle) that explains why observations occur.

Model

A scientific theory that can be visualized, such as the nuclear or planetary model of the atom.

Scientific Law

A concise verbal or mathematical statement of a relationship between phenomena that always holds under stated conditions, describing how matter behaves.

Pure Substance

Matter that has a definite (constant) composition and distinct properties, consisting of only one type of atom, molecule, or group of ions.

Mixture

A combination of two or more substances in which the substances retain their distinct identities and do not have a constant composition.

Element

A substance that cannot be chemically broken down into simpler substances.

Compound

A substance composed of two or more elements chemically bonded together in fixed, definite proportions.

Heterogeneous Mixture

A mixture whose composition varies from one region to another and is not uniform throughout.

Homogeneous Mixture

A mixture whose composition is uniform throughout, also commonly referred to as a solution.

Alloy

A solid solution of metals, such as brass which is a solid solution of copper and zinc.

Physical Properties

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

Chemical Properties

Properties a substance displays only through changing its composition by undergoing a chemical reaction.

Physical Changes

Changes in which matter alters its physical appearance or state, but does not alter its chemical composition or identity.

Chemical Changes

Changes in which matter alters its chemical composition during a chemical reaction, converting reactants into different products.

Mass

A measure of the quantity of matter present in an object, measured in SI units of $\text{kg}$.

Weight

The gravitational force exerted on an object by the planet or moon on which it is located.

Temperature

A measure of hotness or coldness that reflects the average random speeds of the atoms or molecules of a substance.

Absolute Zero

The temperature ($0\,\text{K}$) at which atomic and molecular motion has reached its minimum.

Volume

The amount of space occupied by an object, having an SI derived unit of $\text{m}^3$.

Density

Mass per unit volume of a substance, defined by the relationship $d = \frac{m}{V}$.

Extensive Property

A property that depends on how much matter is being considered, such as length, mass, or volume.

Intensive Property

A property that does not depend on how much matter is being considered, such as density, temperature, or concentration.

Accuracy

How close a measured value is to the true value.

Precision

How consistent repeated measurements are with one another.

Significant Figures

All certain digits plus one estimated digit included in a measured value to reflect measurement precision.