2. Classifying Matter -Vocabulary
Pure Substance: Matter that always has the exact same composition
Element: A substance that cannot be broken down into simpler substances
Atom: The smallest part of an element
Compound: A substance that is made from two or more simpler substances and can be broken
down into those simpler substances
Heterogeneous mixture: The parts of the mixture are noticeably different from one another
Homogeneous mixture: the substances are so evenly distributed that is is difficult to distinguish
one substance in the mixture from another
Suspension: A heterogeneous mixture that separates into layers over time
Colloid: It contains some particles that are intermediate in size between the small particles in the
solution and the large particles in the suspension
3. Key Concepts
Every sample of a given substance has the same properties because a substance has a fixed,
uniform composition
An element has a fixed composition because it contains only one type of atom
A compound always contains two or more elements joined in a fixed proportion
The properties of a mixture can vary because the composition of a mixture is not fixed
4. Breakdown of Matter
Matter
Pure Substance Mixtures
Heterogeneous Homogeneous
Element Compound Mixture Mixture
5. Physical Properties - Vocabulary
Physical property: Any characteristic of a material that can be observed or measured without
changing the composition of the substances in the material
Viscosity: The tendency of a liquid to keep from flowing
Conductivity: A material’s ability to allow heat to flow
Malleability: The ability of a solid to be hammered without shattering
Melting Point: The temperature at which a substance changes from a solid to a liquid
Boiling Point: The temperature at which a substance boils
Filtration: A process that separates materials based on the size of their particles
Distillation: A process that separates the substances in a solution based on their boiling points
Physical change: Something that occurs when some of the properties of a material change
6. Key Concepts
Viscosity, conductivity, malleability, hardness, melting point, boiling point, and density are all
examples of physical properties
Physical Properties are used to identify a material, to choose a material for a specific purpose, or
to separate the substances in a mixture.
Filtration and distillation are two common separation methods
Some physical changes can be reserved while others cannot
7. Temperature
Temperature: A means of measuring heat; also measuring speed at which particles are moving
(faster movement=greater temperatures)
Instruments used: Thermometer
Units: C˚, F˚, K
Celsius: Water boils at 100˚C and freezes at 0˚C
Fahrenheit: Water boils at 212˚F and freezes at 32˚C
Kelvin: Water boils at 373K and freezes at 273K
11. Chemical Properties- Vocabulary
Chemical Properties: Any ability to change in the composition of matter
Flammability: A materials ability to burn in the presence of oxygen
Reactivity : How readily a substance combines chemically with other substances
Chemical change: It occurs when a substance reacts and forms one or more new substances
Precipitate: Any solids that forms and separates from a liquid mixture.
12. Key Concepts
Chemical properties can be observed only when the substances in a sample of matter are
changing into different substances.
Three common types of evidence for a chemical change are a change in color, the production of
gas, and the formation of a precipitate.
When matter undergoes a chemical change, the composition of the matter changes. When
matter undergoes a physical change, the composition of the matter remains the same.
13. Physical vs. Chemical Changes
Example of a physical change- the composition is NOT changed
Example of chemical change- the composition DOES change
14. Review- Question #1
A)What is the difference between a pure substance and a
mixture? B) What are their subcategories
A) Pure substances composition never changes, and a mixture’s
composition will change. B) Pure Substance’s=Compound,
Element. Mixture= Heterogeneous, Homogeneous.
15. Review- Question #2
What is the difference between a colloid, solution, and a
suspension
Colloid= Light cannot go through the substance
Suspension= Mixture, it is layered
Solution= Light can go through it
16. Review- Question #3
What are two separation techniques?
Either distillation, filtration, or evaporation is a separation
technique
17. Review- Question #4
Why are physical and chemical properties used to help identify
certain substances?
They are used because all elements have properties unique to
them.
