2.1 Properties of Matter•Extensive vs. Intensive•Extensive- amount of matter in a sample mass- measure of the amount of matter in an object volume- space occupied by an object•Intensive- type of matter in a sample, not the amount•Substance- matter with a uniform and definite composition•Physical property- a quality or condition of a substance that can be observed or measured without changing the substance’s composition

2.1 Properties of Matter

• States of matter

-Solid: definite shape, definite volume

-Liquid: indefinite shape, definite volume

-Gases: indefinite shape, indefinite volumeVapor: gaseous state of a substance that is generally a

liquid or solid at room temperature

2.1 Properties of Matter

• Physical Changes: -change in the physical property of a substance, but composition of the material does not change

• Physical changes can be classified as reversible or irreversible

2.2 Mixtures

• Mixture: physical blend of two or more components. Classified as either heterogeneous or homogeneous

• Heterogeneous: mixture in which the composition is not uniform throughout

• Homogeneous: mixture in which the composition is uniform throughout

• Phase: any part of a sample with uniform composition and properties

2.2 Mixtures• Separating Mixtures: uses differences in the

physical properties of a sample

Filtration: separating a solid from a liquid in a heterogeneous mixture

Distillation: liquid is boiled to produce a vapor that is then condensed into a liquid

2.3 Elements and Compounds• Element: simplest form of matter that has a

unique set of properties

• Compound: substance that contains two or more elements chemically combined in a fixed proportion

Compounds can be broken down into simpler substances by chemical means, but elements cannot

2.3 Elements and Compounds• Chemical change: change that produces matter

with a different composition than the original matter

-The properties of compounds differ from their component elements

2.3 Elements and Compounds

• Distinguishing between substances and mixtures:

-If the composition of a material is fixed (uniform throughout) the material is a substance

-If the composition of a material varies, the material is a mixture

2.3 Elements and Compounds

• Symbols and Formulas

Chemical symbols- represent elements

Chemical formulas- represent compounds

PB vs Pb

2.4 Chemical Reactions

• Chemical property: the ability of a substance to undergo a specific chemical change

-during a chemical change, the composition of matter always changes

• Chemical reaction: one or more substances change into one or more new substances

-reactant: substance at the start of a reaction

-product: substance produced at the end of a reaction

2.4 Chemical Reactions• Clues that a chemical change has occurred:

-transfer of energy

-change in color

-production of a gas

-formation of a precipitate

• Precipitate: solid that forms and settles out of a liquid mixture

2.4 Chemical Reactions• Law of Conservation of Mass: during any

chemical reaction, the mass of the products is always equal to the mass of the reactants