Solutions
* Definition: A homogeneous mixture where one substance (the solute) is dissolved completely and evenly into another substance (the solvent).
* Particle Size: Solute particles are very small, typically less than 1 nanometer (nm) in diameter.
* Appearance: Transparent, clear, and often colorless.
* Separation: The solute cannot be separated by simple filtration or sedimentation.
* Examples: Saltwater (salt dissolved in water), sugar dissolved in coffee, air (gases dissolved in gases).
Suspensions
* Definition: A heterogeneous mixture where particles of one substance (the solute) are dispersed throughout another substance (the solvent) but are not dissolved.
* Particle Size: Solute particles are relatively large, usually greater than 1000 nm in diameter.
* Appearance: Cloudy, opaque, and the suspended particles can often be seen with the naked eye.
* Separation: The suspended particles can be separated by filtration or sedimentation (they settle out over time).
* Examples: Sand in water, chalk dust in air, muddy water.
Colloids
* Definition: A heterogeneous mixture where particles of one substance (the dispersed phase) are dispersed throughout another substance (the dispersing medium) but are not dissolved.
* Particle Size: Solute particles are intermediate in size, ranging from 1 nm to 1000 nm in diameter.
* Appearance: Often cloudy or opaque, but may have a translucent appearance.
* Separation: The dispersed particles do not settle out easily and cannot be easily separated by filtration.
* Examples: Milk (fat droplets dispersed in water), fog (water droplets dispersed in air), paint (pigment particles dispersed in a liquid).
Key Differences Summary
| Feature | Solution | Suspension | Colloid |
|----------------|--------------------|--------------------|----------------------|
| Particle Size | < 1 nm | > 1000 nm | 1 nm - 1000 nm |
| Appearance | Transparent | Cloudy/Opaque | Cloudy/Translucent |
| Separation | Not filterable | Filterable | Not easily filterable |
| Examples | Saltwater, Sugar in coffee | Sand in water, Muddy water | Milk, Fog, Paint |
Important Note: The distinction between suspensions and colloids can sometimes be blurry, as particle size is not always a definitive factor. The key factor is the stability of the mixture. Suspensions tend to settle out over time, while colloids remain dispersed for longer periods.
