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Chapter 3 & 4 notes
Physical Science Chapter 3
Physical and Chemical Changes
3-1               PHASES  OF  MATTER

Physical Properties: Characteristics of a substance that can be observed without changing the identity of the substance.

Phase is a state in which matter can exist.


solid   definite volume and shape  - usually crystal structure   (Repeating pattern)

liquid   definite volume; takes the shape of the container

gas   no definite volume or shape

plasma   most common phase of matter in the universe

Gas Laws:

Boyle's Law

Charles' Law

Avogadro's Law

Melting point:   Temperature at which a solid changes into liquid.
Freezing:   Phase change from liquid to solid.

Freezing point: Temperature at which a liquid substance becomes solid.

         Freezing Point = Melting Point

3-3
CHEMICAL  PROPERTIES  AND  CHANGES

Chemical Properties:   Describe a substance's ability to change into a different substance.

        Flamability:   The ability to burn (combine with oxygen).


Chemical Changes: Changes that substances undergo when they turn into different substances                                                                                   

Chemical Reaction:  The process by which the                                              substance changes.                                                                                   

Physical Science Chapter 4
Mixtures, Elements, and Compounds
4-1         CLASSES  OF  MATTER

Mixtures
Solutions
Elements
Compounds

Substance:   Classification of material that is either an element or compound.   


A substance cannot be broken  down or separated by physical means.

4-2          MIXTURES

Mixture:   Matter that consists of two or more substances mixed together, but not                               chemically combined.

Substances in mixtures keep their same chemical properties and most of their physical properties.

Chemical composition does not change!
  Substances can be present in any amount.
     Can be separated by physical means.
Types of Mixtures:

Heterogeneous:   Large visible particles, easily separated.

    Colloids:   Mixtures that do not settle out of suspension (smog).

   Suspension:   A heterogeneous mixture containing a liquid in which visible articles settle.

Homogeneous:   Well mixed with even distribution of the substances - particles do not settle out.

    Solution:   Homogeneous mixture of two or more substances in a single physical phase.
         Colloid: homogeneous mixture that does not settle - milk.

        Solute:   substance dissolved ("dissolvee")

        Solvent:   substance that does the dissolving ("dissolver")

Types of solutions   p94
                                                (types & examples)

Solubility: The amount of solute that can completely dissolve in a given amount of solvent at a specific temperature.

Soluble:     can dissolve

Insoluble:   cannot dissolve

Alloys:    Metal solutions
4-3           ELEMENTS

An element is a pure substance
                          - made of only 1 type of substance.

Atom:   Building block of matter - smallest particle of an element that has the same properties as the element.

Chemical Symbols:   1 or 2 letter shorthand for the                                        element's name.

(First letter is always capitalized, but the second letter never is!)

4-4       COMPOUNDS

Compounds are pure substances made up of two or more elements.

A compound usually has very a  different appearance and characteristics from the elements  that  it is made of.

Molecule:   Smallest particle of a compound that retains the properties of the compound.

Chemical Formula:   Shorthand for a chemical                                              substance.

          Subscripts:   Show the ratio of elements in a compound.

Chemical Equations:   Description of a chemical reaction using symbols and formulas.

           Coefficient:   Numbers which balance the equation.