CH. 2MATTER & CHANGE

C. Smith Fall 2014

Properties of MatterMatter is any

substance that has mass and takes up space (volume). All objects contain

matter.

CH. 2 MATTER AND CHANGE.

PHYSICAL PROPERTIES ARE PROPERTIES THAT CAN BE OBSERVED OR MEASURED WITHOUT CHANGING THE SUBSTANCE. THERE ARE TWO TYPES:EXTENSIVE PROPERTIES & INTENSIVE PROPERTIES.

Extensive properties are properties that depend on the amount of matter present.MassLengthVolume

Intensive properties are used to identify a substance.

DensityColorCrystalline shapeMelting and Boiling point

Refractive index

Phases of MatterSolids

Solid particles occupy a regularly fixed position in relation to surrounding particles.Solid particle appears to vibrate around a fixed point.Particles are closely packed and travel a distance equal to only a fraction of their diameter before colliding.Solid particles are arranged in a definite pattern and have definite shape and volume.

Phases of MatterLiquids

Liquid particles do not act independently of each other - motion is limited.Liquid particle slips by each other because the particles have vibratory type of motion.The particles still travel in a straight-line path between collision.Liquids have definitive volume and assume the shape of their container.

PHASES OF MATTER Gases

Gas particles are independent of each other and move in a straight line.Change in

direction occurs only with collisions.Gases assume the

shape and volume of their container.

PHASES OF MATTERPlasma

Plasma is a high energy electrically charged mixture of ions and electrons.Particles that have been ionized

(charged)There exist at extremely high

temperatures.Exist at naturally (stars) or man-

made (neon signs).While plasma is the most abundant

phase of matter in the universe, on earth it only occurs in a few limited places.

Bose-Einstein condensate Extremely dense form of matter. Particle motion slowed down by

decreasing temperature to cease motion. Consider to be super unexcited and

super cold (approaching absolute zero, – 273K)

PHASE CHANGESPhysical changes are changes in the form of a

substance but not in the substance.The substance remains the same after the

change but appears different. (Phase change)Physical changes can be reversible (but not

always).Examples of phase changes

MeltingFreezingBoiling/Vaporization CondensationEvaporationSublimation

MIXTURES- CLASSIFYING MIXTURESHETEROGENEOUS MATERIAL

Heterogeneous means more than one type of substance. Heterogeneous matter exists in the form of mixtures.A mixture is matter that consists of two or

more different materials.Mixtures can be separated by physical

means. (distillation and filitration) Mixtures have phases, which are any

region with a uniform set of properties.The boundaries between these phases are

called interfaces.

HOMOGENEOUS MATERIALHomogeneous means only one type of a

substance.Homogeneous matter is matter that is

uniformly mixed and cannot be separated easily.

Homogeneous matter exist in several forms:

Pure Substances- Elements & CompoundsSolutions

Solutions consist of solute (dissolved material) and solvent (dissolving material).Solute particles are very small and are

scattered in the solvent and appear as uniform.

Solutions are not always liquid.

CHEMICAL REACTIONS CHANGING REACTANTS TO PRODUCTS

Chemical changes are changes in which a new substance with different characteristics from the original substance is produced.

There are several examples of chemical changesBurningDigestionFermentingCorrosion

Chemical Reactions Changing Reactants to Products

Chemical properties describe the reaction of a substance with other material or the reaction within the substance itself. Lack of chemical reactivity is also important.

The evidence of a chemical reaction Color ChangeFormation of a gasTemperatures change.OdorPrecipitate (solid)

CONSERVATION OF MASSDuring a chemical reaction, the quantity of matter is unchanged. The mass of products is always equal to the mass of reactants. The same can be said for physical changes.This is known as the Law of Conservation of Mass. The law states that mass can neither be created nor destroyed, it is conserved. Some of the mass can be in the form of energy or a gas.

ELEMENTS AND COMPOUNDSDISTINGUISHING BETWEEN ELEMENTS AND COMPOUNDS

There are two types of pure substances.

Elements Compounds.

Substances made of only one kind of atom are called elements.Substances made of more than one kind of substances are called compounds.

ELEMENTS: SIMPLIST KIND OF MATTER Elements are the

building blocks for all other substances.Cannot be broken down

into simpler substances.All atoms of an element

have the same number of protons. There are 109 of these

currently listed and named on the Periodic Table

ELEMENTS: 4 BASIC TYPES OF ELEMENTS Metals: found on the left and center of the Table of Elements Non-metals: found on the

right side of the Table of Elements Metalloids: found along

the stair-step line Synthetic: made in the

laboratory and not yet found in nature – many of the Actinide and Lanthanide series and very large # elements.

When they are broken down, the pieces have completely different properties than the compound.

Compound- Made of molecules- two or more atoms

can be separated into simpler substances only by chemical means.Molecules are the smallest particle of a compound that retains its properties and it is composed of 2 or more atoms.

Compounds

SYMBOLS AND FORMULASEach element is

represented by one- or two- letter chemical symbol. The symbols for most

elements consist of the first one or two letters of the element’s name.

A chemical formula is a combination of symbols that represents the composition of a compound.A formula shows two things:

1.The elements present in the compound2. The relative number of atoms of each element in the compound.

Example H2O

Formulas often contain numerals to indicate the ratio of elements in the compound.The numbers used in the formula are called subscripts.

Matter

Mixture Pure Substance

ElementCompoundHeterogeneous Mixture

Homogeneous Mixture

Can be separated physically

Cannot be separated physically

Can see the parts

Cannot see the parts

Can be separated chemically

Cannot be separated

Most impure Most pure

suspension colloid

Work Cited

Nichols, Nancy : Klein Collins Science specialist (Ret.)

Textbook: Chemistry , Wilbraham, Staley, Matta, Waterman; Pearson Realize