Chapter 1

Property

A characteristic that belongs to a person or thing.

Matter

Anything that has mass and takes up space.

Chemistry

The study of matter and how it changes.

Substance

A single kind of matter that is pure.

Physical Property

A characteristic of a substance that can be observed without changing it into another substance.

Chemical Property

A characteristic of a substance that describes its ability to change into another substance.

Element

A substance that cannot be broken down into any other substance.

Atom

The basic particle from which all elements are made.

Chemical Bond

Atoms combine with other atoms.

Molecule

A group of 2 or more atoms held together by chemical bonds.

Compound

A substance made of 2 or more elements that are chemically combined in a set ratio.

Mixture

Made up of 2 or more substances that are together in the same place but the atoms are not chemically bonded.

Heterogeneous Mixture

A mixture where you can usually see the different parts and can be easily separated.

Homogeneous Mixture

A mixture where the substances are evenly mixed and it's difficult to see the different parts or separate them.

Physical Change

Alters the form or appearance of matter but does not turn any substance into a different one.

Chemical Change

Produces one or more new substances that have different properties.

Law of Conservation of Mass

Matter cannot be created or destroyed in a chemical or physical change; it can only be changed.

Energy

The ability to do work or make a change.

Endothermic Change

A change where energy is absorbed.

Exothermic Change

A change where energy is released.