Chemistry Basics: Matter, States, and Properties for Students

What is chemistry?

The study of matter and its changes.

What is matter?

Anything that occupies space and has mass.

What is a pure substance?

Matter with a fixed chemical composition and characteristic properties.

What are the two types of pure substances?

Elements and compounds.

What is an element?

A substance that cannot be broken down into simpler substances, composed of one kind of atom.

What is a compound?

A substance composed of two or more elements.

What are atoms?

The almost infinitely small building blocks of matter.

What are molecules?

Made up of two or more atoms in a specific shape.

What is a homogeneous mixture?

A mixture where all materials are in the same state and uniform throughout, also called a solution.

What is a heterogeneous mixture?

A mixture where the composition is not completely uniform.

What is filtration?

A method used to separate heterogeneous mixtures by separating insoluble solids from liquids.

What is distillation?

A method used to separate homogeneous mixtures.

What are physical properties?

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

What are extensive properties?

Properties that depend on the amount of sample, such as mass and volume.

What are intensive properties?

Properties that do not depend on the amount of sample, such as temperature and melting point.

What are chemical properties?

Properties that describe how a substance may change or react to form other substances.

What is a physical change?

A change in which no chemical bonds are broken or formed.

What is a chemical change?

A change that occurs when chemical bonds are broken and formed between molecules or atoms.

Give an example of a physical change.

Ripping paper or melting ice.

Give an example of a chemical change.

Burning paper or iron rusting.