Classification of Matter Chapter 15. Composition of Matter – Sec. 1 Pure Substances – Same...

Classification of MatterClassification of Matter

Chapter 15

Composition of Matter – Sec. 1Composition of Matter – Sec. 1 Pure Substances

– Same composition throughout– Either an element or compound

Element– All one type of atom– Everything made of atoms

Compound– Atoms of two or more elements chemically bonded

together

Composition of MatterComposition of MatterMixtures

– Made of two or more substances that can be easily separated by physical means

Heterogeneous Mixture– Different materials can be seen easily– Granite, concrete, vegetable soup

Homogeneous Mixture (Solution)– Blended evenly throughout– Vinegar, Kool-aid

MATTER

Can it be separated?

Mixtures Substance

Homogeneous Mixture

Air, sugar water, stainless stell

Heterogeneous Mixture

Granite, wood, blood

Compounds

Water, sodium chloride

Elements

Gold, aluminum

yes no

MixturesMixturesColloid ~ heterogeneous

– Particles larger than solution but not heavy enough to settle out

– Milk, paint, fog and smokeDetecting Colloids

– Pass a beam of light through it Colloid – See beam Solution – Cannot see beam

– Particles big enough to scatter light – Tyndall Effect

MixturesMixturesSuspension ~ heterogeneous

– Not solution, not colloid– Muddy pond water– Heterogeneous mixture with a liquid and

visible particles that settle

Properties of MatterProperties of Matter

Section 2

Physical PropertiesPhysical Properties

Def: characteristic observed without changing the identity of the material– Ex: color, shape, size, density

AppearanceBehavior

– Magnetic, malleable, flow of liquid

Separating MixturesSeparating Mixtures

Sand and Rock mixture?– Filter or sift

Iron filings and Aluminum mixture?– Magnet

Physical ChangePhysical Change

Change in size, shape or state of matter and identity is same– Solid to a liquid?– Yes

Solid Liquid Gas

Melt Evaporate

CondenseFreeze

Physical ChangePhysical Change

How to get pure water from salt water?– Distillation – evaporate liquid and then

recondense it

Chemical Properties and Chemical Properties and ChangesChanges

Chemical Property – can be observed only by changing the substance– Flammability, reactivity, decomposition

Chemical Change – change where a NEW substance is formed

Weathering – Physical or Chemical Change?– Both!

Law of Conservation of MassLaw of Conservation of Mass

Matter is neither created nor destroyed during a chemical reaction

Mass of all substances before = mass of all substances after change