Matter and ItsProperties

Volume is the amount of three dimensional spacean object occupies.

Mass is a measure of the amount of matter.

Matter is anything that has mass and takes up space.

Basic Building Blocks of Matter

An atom is the smallest unit of an element thatmaintains the chemical identity of that element.

An element is a pure substance that cannot be broken down into simpler, stable substances and is made of one type of atom.

A compound is a substance that can be broken down into simple stable substances. Each compound is made from the atoms of two or more elements that are chemically bonded.

Example: NaCl (Table Salt)

Sugar

Properties and Changes in Matter

Extensive properties depend on the amount of matter that is present.• volume•mass• the amount of energy in a substance

Intensive properties do not depend on the amountof matter present.•melting point• boiling point• density• ability to conduct electricity• ability to transfer energy as heat

Physical Properties and Changes

A physical property is a characteristic that can beobserved or measured without changing the identity of the substance.•melting point and boiling point

A physical change is a change in a substance thatdoes not involve a change in the identity of thesubstance.• grinding, cutting, melting, and boiling

A change of state is a physical change of a substance from one state to another.• states of matter – solid state, liquid state, gas state, plasma

In the solid state, matter has definite volume anddefinite shape.

Particle MovementExamples

In the liquid state, matter has a definite volumebut an indefinite shape.

Particle Movement

Examples

In the gas state, matter has neither definite volumenor definite shape.

Particle Movement

Examples

Plasma is a high-temperature physical state of matter in which atoms lose most of their electrons,particles which make up atoms.Matter enters the plasma state when it is heated to such a high temperature that some of the atoms begin to break apart.

The negatively chargedelectrons (yellow) arefreely streaming through the positivelycharged ions (blue).

Plasma Examples

Plasma can be found in stars, fluorescentlight bulbs, Cathode ray tubes, neon signs, and lightening.

Chemical Properties and ChangesA chemical property relates to a substance’s abilityto undergo changes that transform it into differentsubstances.

For example, the ability of charcoal (carbon) toburn in air is a chemical property.

A change in which one or more substances areconverted into different substances is called a chemical change or chemical reaction.

The fireworksdisplay at right is an example of a reaction that releasesheat and light.

The reactants are the substances that react in achemical change.The products are the substances that are formedby the chemical change.

example: The following chemical equation shows that the reactant ammonium dichromate yields the products nitrogen, chromium(III) oxide, and water.

)g(OH4)s(OCr)g(N)s(OCr)(NH 23227224

Reactant Products

Classification of MatterA mixture is a blend of two or more kinds of matter, each of which retains its own identityand properties.

•mixed together physically• can usually be separated

Would the pizza be amixture?

Homogeneous mixtures are called solutions.• uniform in composition (salt-water solution).

Soft drinks in sealed bottles are examples of homogeneous mixtures.

Heterogeneous mixtures• not uniform throughout (clay-water solution)

Pizza is an example ofa heterogeneous mixture.

Pure SubstancesA pure substance has a fixed composition.Pure substances are either compounds or elements.

Compound Element

A pure substance differs from a mixture in the following ways:

• Every sample of a given pure substance has exactly the same characteristic properties.

• Every sample of a given pure substance has exactly the same composition.

•Water is always 11.2% hydrogen and 88.8% oxygen by mass.

Classification of Matter