Everything MATTERs

MATTER – anything that takes up space and has mass.

3 States of Matter

1. SOLID

·        has a definite shape (rigid)

·        definite volume

·        particles vibrate around fixed positions

2. LIQUID

·        No definite shape (takes the shape of its container)

·        Has definite volume

·        Particles are free to move over each other, but are still attracted to each other

3. GAS

·        No definite shape (takes the shape of its container)

·        No definite volume

·        Particles move in random motion with little or no attraction to each other

·        Highly compressible

Matter can be sub-divided into mixtures and pure substances.

1.  MIXTURE – has variable composition, the proportions that make up the mixture vary and can be separated by physical methods.

Mixtures can be classified as homogeneous or heterogeneous.

A.                             HOMOGENEOUS – it has only one phase; having visibly (to the naked      eye) indistinguishable parts.

              Example: red wine in a glass

B.                              HETEROGENEOUS – it has two or more phases; having visibly distinguishable parts.

Example: fruit salad in a bowl

		Solution	Suspension	Colloid
	Appearance	Clear, transparent and homogeneous	Cloudy, heterogeneous, at least two substances visible	Cloudy but uniform and homogeneous
	Particle Size	molecule in size	larger than 10,000 Angstroms	10-1000 Angstroms
	Effect of Light Tyndall Effect	none -- light passes through, particles do not reflect light	variable	light is dispersed by colloidal particles
	Effect of Sedimentation	none	particles will eventually  settle out	none

A solution is always transparent, light passes through with no scattering from solute particles which are molecule in size. The solution is homogeneous and does not settle out. A solution cannot be filtered but can be separated using the process of distillation.


Example: A mixture of salt and water.

A suspension is cloudy and heterogeneous. The particles are larger than 10,000 Angstroms which allows them to be filtered. If a suspension is allowed to stand the particles will separate out.


Example: Milk in a glass of water

A colloid is intermediate between a solution and a suspension. While a suspension will separate out a colloid will not. Colloids can be distinguished from solutions using the Tyndall effect. Light passing through a colloidal dispersion, such as smoky or foggy air, will be reflected by the larger particles and the light beam will be visible.

2. PURE SUBSTANCES – have constant composition and can only be separated by chemical reactions.

Elements and compounds are pure substances.

ELEMENTS -  substances that cannot be decomposed into simpler substances by chemical or physical means.

COMPOUNDS – substance with constant composition that can be broken down into elements by chemical processes.

Pure substances get broken down in the process of chemical changes.  Chemical changes involve a change in color, change in temperature, change in odor, or a gas is given off.

Mixtures can be separated by physical changes.  A physical change may change the form of a substance, but not its chemical compositions

METHODS FOR SEPARATING MIXTURES

1. Distillation – process of separating a mixture by differences in boiling point.

2. Filtration – process of separating a solid and a liquid.

3. Chromatography – a method of separation that requires 2 phases, a stationary phase and a mobile phase.

• STATIONARY PHASE – a solid
• MOBILE PHASE -  a liquid or gas

           Example:  Paper Chromatography

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