Chapter 1: Introduction: Matter, Energy, and Measurement Vocabulary

A set of key vocabulary terms and definitions from Chapter 1 covering classifications of matter, properties, changes, energy, and measurement concepts.

Chemistry

The study of matter, its properties, and the changes it undergoes.

Matter

Anything that has mass and takes up space.

Substance

Matter that has distinct properties and a composition that does not vary from sample to sample.

Element

A substance which cannot be decomposed to simpler substances.

Compound

A substance which can be decomposed to simpler substances because it is made up of more than one element.

Atoms

The building blocks of matter.

Molecules

Groups of attached atoms that represent connections between atoms seen in nature.

Law of Constant Composition

Also known as the Law of Definite Proportions, this law states that compounds have a definite composition, meaning the relative number of atoms of each element in the compound is the same in any sample.

Solution

Another name for a homogeneous mixture, which has the same composition throughout the sample.

Physical Properties

Properties that can be observed without changing a substance into another substance.

Chemical Properties

Properties that can only be observed when a substance is changed into another substance.

Intensive Properties

Properties that are independent of the amount of the substance present, such as density, boiling point, or color.

Extensive Properties

Properties that depend upon the amount of the substance present, such as mass, volume, or energy.

Physical Changes

Changes in matter that do not change the composition of a substance, such as changes of state, temperature, and volume.

Chemical Changes

Changes that result in new substances, such as combustion, oxidation, and decomposition.

Filtration

A technique used to separate solid substances from liquids and solutions.

Distillation

A separation method that uses differences in the boiling points of substances to separate a liquid homogeneous mixture into its components.

Chromatography

A technique that separates substances on the basis of differences in their ability to adhere to a solid surface.

Energy

The capacity to do work or transfer heat.

Work

The energy transferred when a force exerted on an object causes a displacement of that object.

Heat

The energy used to cause the temperature of an object to increase.

Force

Any push or pull on an object.

Kinetic Energy

The energy of motion, depending on an object's mass and its velocity.

Potential Energy

Stored energy that depends on an object's relative position compared to other objects.

Absolute Zero

The lowest possible temperature, defined as $0\,K$, based on the properties of gases.

Precision

A measure of how closely individual measurements agree with one another.

Accuracy

Refers to how closely individual measurements agree with the correct, or "true," value.

Significant Figures

All the digits of a measured quantity, including the uncertain ones.

Dimensional Analysis

A method used to change units by applying conversion factors that are equalities.