Classifying matter

Post on 22-Feb-2016

27 views 0 download

Tags:

description

Classifying matter. Ch. 2. Pure Substances. - matter that always has the same composition Every sample of the substances always has to same properties Uniform composition, fixed properties. Elements. Cannot be broken down into simple substances - PowerPoint PPT Presentation

transcript

CLASSIFYING MATTERCh. 2

True False Statement True False

An compound is an example of a pure substance

Heterogeneous mixtures are the same throughout

Colloids scatter light, and an example is fog

Suspensions are mixtures that will separate into layers

Sugar and water is a homogeneous solution

Pure Substances - matter that always has the same

composition Every sample of the substances always has

to same properties Uniform composition, fixed properties

Elements Cannot be broken

down into simple substances

Contains only 1 type of atom(smallest particle of an element)

Symbols 1st letter always

capitalized, 2nd never

Same globally Ex:

Compounds Substance made

of 2 or more simpler substances

Can be broken down into simpler substances

Properties differ from the elements in which its made

Has a fixed proportion

Ex:

Mixtures Retain some properties of individual

substances Composition is not fixed

Mixtures

Different types of substances

Unevenly mixed

Appears to be only 1 substance

Evenly mixed

Heterogeneous Homogenous

Solution Homogenous Mixtures Particles are too small- to settle out, to

be trapped by filter, or scatter light Ex:

Suspension Heterogeneous Mixtures Separates into layers over time Particles are trapped by filters, and can

scatter light Ex:

Colloid Heterogeneous Mixture Particles never settle out Scatter light= Tyndall Effect Ex:

PHYSICAL PROPERTIESCh. 2.2

True False Statement True False

The greater the viscosity, the faster a substance moves

Malleability is the ability to be hammered without shattering

Physical changes don’t change the substance, and can be reversed

Distillation separates substances based on melting points

Physical properties help us choose materials to use

Physical Properties Characteristics of matter Observed/ measured without changing

the composition

Physical Properties

Resistance to flow High viscosity=

slow Low viscosity=

fast Decreases with

heat

Ability for heat to flow

High conductivity= conductors

Viscosity Conductivity

Physical Properties

Ability to be hammered without shattering

Ability to scratch another surface

Diamond- hardest known material

Malleability Hardness

Physical Properties

Temp. which solid turn liquid- melting point

Temp. which liquid turns gas- boiling point

Test purity of a substance

Melting/Boiling Points Density

Using Physical Properties ID Materials

1-decide which properties to test

2-test the sample of unknown

3- compare results to known

Choose Materials Look at properties

for specific uses

Using Physical Properties Filtration

Process that separates materials based on particle

Distillation Process that

separates substances based on boiling points

Physical Change Properties change Substances materials remain the same!

2.3Chemical Properties

True False Statement True False

Flammability is the ability to burn in the presence of nitrogen

Change in color is a chemical change

Formation of a solid is a precipitate

Chemical changes alter the composition of the original

substanceRust is an example of a chemical

change

Chemical Properties Ability to produce a change in the

composition of matter 1 substance changes into another

Chemical Properties

Ability to burn in presence of oxygen

How readily a substance combines chemically with other substances

Flammability Reactivity

Chemical Change 1 substances reacts with another to form

1 or more new substances

Signs of Chemical Change Color Change-

Production of Gas-

Formation of Precipitate-