Chapter 5

State Standards: 3.b; 5.a; 7.c

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Chapter 5-1: Elements

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ElementsAn element is made up of only one type of atom

(particle)

It is a pure substance that cannot be separated into simpler substances

A pure substance is when all the atoms (building blocks) are identical within the substance

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4http://facstaff.gpc.edu/~pgore/PhysicalScience/periodic-table.gif

Classifying ElementsElements are classified according to their

characteristic properties (physical & chemical)

Physical: hardness, melting point, density, thermal conductivity, color, etc.

Chemical: reactivity and flammability

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Grouping Elements3 Major Groups:

Metals: shiny, conduct heat and electrical current

Nonmetals: do not conduct heat or electric current, solid nonmetals are dull in appearance

Metalloids: have properties of both metals and nonmetals

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https://chemistry.twu.edu/tutorial/PER4.Gif7

Chapter 5-2: Compounds

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CompoundsCompounds are made by chemically combining

two or more elements

Chemically combine to form a new substance with different properties

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Proteins are found in all living things

Properties of CompoundsCompounds have their own unique physical and

chemical properties

Physical: melting point, density, and colorChemical: reactivity

Combine in specific ratios

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Breaking Down CompoundsSince compounds can only be formed

chemically, they can only be broken down through a chemical change

Usually requires energy in the form of

heat or electrical current

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Common CompoundsVinegar (acetic acid)

Baking Soda (sodium bicarbonate)

Table Salt (sodium chloride)

Carbonated Water (carbonic acid)

Citric Acid

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NaHCO3

NaCl

CH3COOH

H2CO3

C6H8O7

Chapter 5-3: Mixtures

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MixturesCombination of two or more substances that are

not chemically combined

Materials do not react to form a compound

Elements in a mixture keep their original properties (characteristic properties)

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Physically Separating MixturesUsing a magnet

Centrifuge – separates mixtures based on densities

Filtering

Evaporating – heating

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SolutionSolution is a homogeneous (evenly mixed)

mixture containing two or more substances

A simple solution is two substances that are going to be combined. Solute - the substance to be dissolved

Soluble – able to dissolve Insoluble – unable to dissolve

Solvent - the one doing the dissolving*substance with largest amount is solvent

Can be gases, liquids or solids16

Concentration of SolutionsThe amount of a dissolved substance in a

volume of mixture/solution (g/mL)

Solubility – how well a solute can dissolve in a solvent

17Same amount of solute, different amount of solvent.

Same amount of solvent, different amount of solute.

Concentrated Diluted

Examples of SolutionsStates Examples

Gas in gas Air (oxygen in nitrogen)

Gas in liquid Soft drinks (carbon dioxide in water)

Liquid in liquid Antifreeze (alcohol in water)

Solid in liquid Salt water (salt in water)

Solid in solid Brass (zinc in copper)

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Ex: Sugar in water vs. Sand in water.

Sugar dissolves and is spread throughout the glass of water. The sand sinks to the bottom. The sugar-water could be considered a solution. The sand-water is a mixture.

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