Chapter 2 in hard cover text

2.1 PROPERTIES OF MATTERDescribing MatterExtensive Properties – a property that

depends on the amount of matter in a sample.MASS and VOLUME

Intensive Properties – a property that depends on the type of matter in a sample, not the amount of matter

HARDNESS, COLOR, and OTHER QUALITIES

Identifying SubstancePure Substance – matter that has uniform

and definite compositionEvery sample of a pure substance has

identical intensive properties because every sample has the same composition

Physical Property – quality or condition of a substance that can be observed or measured w/o changing the composition

temperature, hardness, color, conductivity, and malleability

States of MatterSolid – has definite shape and volume. The

shape of a solid does not depend on the shape of the container. Particles are tightly packed in a rigid orderly arrangement.

Liquid – has definite volume and indefinite shape. Particles are on close contact with one another and the container, yet are not in a rigid or orderly arrangement. Particles are free to flow from one location to another and take the shape of the container.

States of Matter (con’t)Gas – has indefinite shape and indefinite

volume. Meaning that it takes the shape and volume of the container. Particles are much farther apart then the particles in a liquid. Because the space between particles gases are easily compacted into smaller volumes.

Physical ChangesDuring a physical change some of the

properties of a substance can change but the composition of the material does not

Reversible – boil, freeze, melt, and condenseIrreversible – break, split, grind, cut, crush

2.2 MIXTURESClassifying MixturesMixture – physical blend of two or more

componentsBased on their components mixtures can be

heterogeneous or homogeneousHeterogeneous Mixture – mixture in which the

components are not uniform throughoutHomogeneous Mixture – mixture in which the

composition is uniform throughout Ex. A solutionPhase – used to describe any part of a substance

that is uniform throughout. Hetero – 2 or more phases Homo – only 1 phase

Separating MixturesDifferences in physical properties can be

used to separate mixturesFiltration – the process of separating solid

from a liquid by using a filter of some sort Example: pasta and water

Distillation – a liquid is boiled to create vapor and cooled in a separate chamber and collected back to a liquid

2.3 ELEMENTS AND COMPOUNDSDistinguishing Elements & CompoundsElements – simplest form of matter that has

unique set of propertiesCompounds – made of 2 or more elements

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

Breaking Down CompoundsChemical Change – a change that produces

matter with a different chemical composition then the original matter

Examples: cooking, baking, chemical reaction

Properties of Compounds – in general the properties of compounds are very different then their component elements

Distinguishing Substances and MixturesIf the composition of a material is

fixed (can’t change), the material is a pure substance. If the composition of a material may vary, the material is a mixture.

Symbols and FormulasChemists use chemical symbols to represent

elements and chemical formulas to represent compounds

Elements have a one or two letter chemical symbol. The first letter is always capitalized. When a second letter is present, it is always lowercase.

Formulas have the symbols together w /o spaces and each element keeps its capital letter. Subscripts denote multiple parts of an element

Example: H2O, C6H12O6

2.4 Chemical ReactionsChemical ChangesChemical Property – the ability of a substance to

undergo a specific chemical changeDuring a Chemical Change , the composition of

the matter always changes.Chemical Reaction – another name for a chemical

change. One or more substances change into one or more new substances during the process.

Reactant – the substance ate the start of the chemical reaction

Product – the substance produced or the result of a chemical reaction.

Recognizing Chemical ChangesPossible clues to chemical change include a transfer of energy, a change of color, production of a gas, or the formation of a precipitate.

Precipitate – solid that forms and settles out a liquid mixture

Conservation of MassDuring a chemical reaction, the mass of the products is always equal to the mass of the reactants.