Matter

Matter can be classified into two main groups:

Mixtures and Substances.

Mixtures

• Classified as either homogenous or heterogenous
• Combination of two or more substances
• Each component retains characteristic properties
• Components can be easily separated
  
  Ex: Pepperoni Pizza
  
• Combination of two or more substances (crust, cheese, sauce, pepperoni)
• Each component retains characteristic properites (you can taste the cheese AND the pepperoni AND the crust...they tastes don't blend together like a cake)
• Components can be easily seperated (if you don't like pepperoni you can peel it off

Homogenous

• Homo - same
• Homogenous solutions look the "same" throughout
• They have a uniform composition
• Consist of more than one phase of matter
• Solute - part of the solution that gets dissolved
• Solvent - part of the solution that does the dissolving

Ex: Kool-Aid

• Made of two phases: 1) Solid - sugar and powder 2) Liquid - water
• Cannot see the solid and liquid seperately, all looks the same
• Solute - Sugar
• Solvent - Water

Heterogenous

• Hetero - different
• You can see the different parts

Ex: T-Bone steak

• Does not all look the same
• You can see the fat, the bone, and the meat

Substances

Classified as either an element or a compound.

Element

• Elements are pure substances
• Simplest form of Matter
• Elements can be found on the PT
• Elements are written by their Chemical Symbol.
• Contain one capital letter

Ex: Gold

• Gold is a pure substnace
• Gold can be found on the PT
• Gold is written Au
• There is only one capital letter in its symbol

Compounds

• Combination of Elements
• Have two or more elements in their chemical symbol
• Have two capital letters in their symbols
• Elements do not retain characteristic properties
• Not easily separated

Ex: Salt

• Salt is a combination of the elements Sodium and Chlorine
• Salt is written NaCl
• There are two capitol letters.
• Sodium and Chlorine blend together to create a compound with new chemical properties

Chemical and Physical Changes

There are two types of change that matter can undergo:
1) Chemical
2) Physical

Chemical Change
Any change that results in the formation of new chemical substances.

Key Words: reacts, forms, rusts, decomposes, digests, burns, forms, releases a gas, acid, cook

Ex:

• gasoline burning - produces water vapor and CO2
• eggs cooking - proteins uncoil and coil into a new form
• bread rising - yeast converts carbohydrates into CO2 gas
• milk souring - lactic acid is produced
• suntanning - vitamin D and melanin are produced

Physical Change

Any change that doesn't affect the internal structure of molecules. Any change that does not result in the formation of a new substance.

Key Words: cut, break, any phase change (melt, boil, condense, etc) , dissolve

Ex.

• whipping egg whites - air is forced into the fluid, no new substance is produced
• magnetising a compass needle - realigns groups of iron atoms, no new product is produced
• boiling water - heats water, changes its state, does not produce a new product
• dissolving sugar in water - sugar molecules disperse within the water, the individual sugar molecules are unchanged
• dicing potatoes - separates molecules, but you still have potatoes

Websites:

This website is a quiz on physical and chemical changes.
This website is a short review and a quiz.
This website discusses physical and chemical changes in depth and has links to other content areas of matter.

Chemical and Physical Properties of Matter

There are two categories that properties of matter can be broken down into:
1) Physical
2) Chemical

Physical Properties
Any characteristic that you can observe without changing the substance that makes up the material
i.e. the appearance.

Ex.

• Shape
• Color
• State of matter
• Measurement
• Odor
• Magnetism - force of attraction or repulsion that acts at a distance (magnets)
• Conductivity - ability to carry an electrical charge
• Malleability - ability to be hammered into sheets
• Ductility - ability to be drawn into wire
• Melting point
• Boiling point
• DENSITY

Chemical Properties
Characteristics of a substance that tell if the substance can undergo a chemical change.

Ex.

• Combustibility - ability/readiness to combust
• Flammability - ability/readiness to catch fire
• Reactivity to air - reacts to exposure to air
• Reactivity to light - ex. photo film paper
• Acidity (pH)

Websites

This website has a brief review and quiz.
This website breaks down the differences in a chart. Very informative.
This website has great notes, quizzes, and worksheets.

States of Matter

There are 3 main states of matter

1) Solid (s)
2) Liquid (l)
3) Gas (g)

State Changes

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States of Matter

States of matter are described based on 4 things:

1. Particle proximity - how close the particles are to each other
2. Compressibility - if the particles can be pushed (compressed) closer to each other
3. Definite/non definite shape
4. Definite/non definite volume

Solid

• Solid particles are very close together
• Particles are incompressible
• Solids have a definite shape
• Solids have a definite volume

Liquid

• Particles are not as close as those in a solid
• Particles are slightly compressible
• No definite shape
• Do have a definite volume

Gases

• Particles are very far apart
• Particles are very compressible
• No definite shape
• No definite volume

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