Lesson 1: Introduction to Chemistry: The Scientific Method, Matter, and Its Properties

A set of vocabulary flashcards covering the introductory concepts of chemistry, including the scientific method, the states and classification of matter, mass versus weight, the law of conservation of matter, and physical and chemical properties.

Chemistry

The study of matter.

Scientific method

The basic tenet in all scientific experimentation, typically starting with an observation, proceeding to a hypothesis, and developing into a theory or law after testing.

Hypothesis

A tentative explanation of observations that acts as a guide for gathering and checking information.

Theory

A well-substantiated, comprehensive, testable explanation of a particular aspect of nature.

Law

A statement that summarizes a vast number of experimental observations and describes or predicts some aspect of the natural world.

Solid

A physical state of matter that is rigid, possesses a definite shape, and has a fixed volume.

Liquid

A physical state of matter that flows, takes the shape of its container, forms a horizontal surface, and has a fixed volume.

Gas

A physical state of matter that takes both the shape and volume of its container, expanding to fill it.

Plasma

The fourth physical category of matter, similar to a gas but containing an appreciable number of electrically charged particles; it is the most abundant form of matter in the universe and present in the Sun and stars.

Mass

A measure of the amount of matter in an object.

Weight

A property that relates to the force that gravity exerts on an object.

Law of conservation of matter

A fundamental law stating that there is no detectable change in the total quantity of matter present when matter converts from one type to another (such as in a chemical change or physical change).

Atom

The smallest particle of an element that has the properties of that element and can enter into a chemical combination.

Element

A pure substance that cannot be broken down into simpler substances by chemical equations.

Compound

A pure substance that can be broken down into simpler substances by chemical reactions.

Mixture

Matter composed of two or more types of matter that can be separated by physical changes.

Heterogeneous mixture

A mixture that can vary in composition from point to point, such as chunky beef stew or chocolate chip cookies.

Homogeneous mixture

A mixture that is uniform in nature throughout, such as coffee (black or with cream).

Physical property

A characteristic of matter that is not associated with a chemical change, such as density, color, hardness, melting and boiling points, and electrical conductivity.

Physical change

A change in the state or properties of matter without any accompanying change in its chemical composition (the identities of the substances contained in the matter).

Chemical property

A characteristic that can be observed during or after a change of one type of matter into another type, such as flammability, toxicity, acidity, reactivity, and heat of combustion.

Chemical change

A change that always produces one or more types of matter that differ from the matter present before the change.

Extensive properties

Properties of matter that are proportional to the amount of matter present.

Intrinsic properties (intensive properties)

Properties of matter that are present no matter how much or little matter is present.