SECTION TWO NOTES

MATTER

• Anything that has mass or takes up space

ELEMENT

• Substance that can't be broken down

ATOM

• Smallest unit of an element
• Keeps the elements chemical properties

MOLECULE

• Smallest unit of a substance
• Behaves like the substance

COMPOUND

• A substance made up of atoms of different elements

PURE SUBSTANCE

• A sample of matter
• A single element or compound
• Has definite chemical and physical properties

MIXTURE

• A combination of 2 or more substances
• Are not chemically combined

HETEROGENOUS

• is a material system made up of two or more different substances se
• which are mixed but are not combined chemically

HOMOGENOUS

• Equally and evenly mixed

DENSITY

• degree of consistency measured by mass per unit volume

PHYSICAL CHANGES

• a change from one state (solid or liquid or gas) to another without a change in chemical composition

CHEMICAL CHANGES

• any process determined by the atomic and molecular composition and structure of the substances

THE END