Classifying matter Ch. 2

An compound is an example of a pure substance True False Statement 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 Heterogeneous Homogenous Different types of substances Unevenly mixed Appears to be only 1 substance Evenly mixed

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 properties Ch. 2.2

The greater the viscosity, the faster a substance moves True False Statement 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 Conductivity Resistance to flow High viscosity= slow Low viscosity= fast Decreases with heat Ability for heat to flow High conductivity= conductors

Physical Properties Ability to be hammered without shattering Malleability Hardness Ability to be hammered without shattering Ability to scratch another surface Diamond- hardest known material

Physical Properties Temp. which solid turn liquid- melting point Melting/Boiling Points Density Temp. which solid turn liquid- melting point Temp. which liquid turns gas- boiling point Test purity of a substance

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!

2.3 Chemical Properties

Flammability is the ability to burn in the presence of nitrogen True False Statement 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 substance Rust 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 Flammability Reactivity Ability to burn in presence of oxygen How readily a substance combines chemically with other substances

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-