Short answer
A solution is uniform at the scale of dissolved molecules or ions: saltwater is a familiar example. A suspension contains larger dispersed particles that can settle, such as muddy water. Colloids such as milk fall between simple textbook examples, so cloudiness alone is not a perfect test. 1 2
Both are mixtures, but particle scale, uniformity and settling behavior differ.
On this page
At a glance
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| Question | Solution | Suspension |
|---|---|---|
| Uniformity | Homogeneous | Heterogeneous |
| Particles | Molecules or ions | Larger dispersed particles |
| Settles on standing? | Normally no | Can settle |
The table summarizes the cited definitions and the article’s stated scope. 1 2
What each thing is
Solution. A homogeneous mixture in which dissolved species are dispersed at molecular or ionic scale and do not settle out. 1
Suspension. A heterogeneous mixture containing dispersed particles large enough that they can settle out over time. 2
Key differences
OpenStax distinguishes dissolved species from suspended particles and separately describes colloids. In a solution, dissolved material is not a visible floating grain; in a suspension, solid or other dispersed matter remains as a separate phase. 1 2
How to tell them apart
Let the mixture stand and observe whether material settles; inspect whether particles can be filtered by ordinary means. These are clues, not definitive tests for every system. A lab may use particle-size measurements. 1 2
Where they overlap
Both contain more than one substance and can look uniform when freshly mixed. Stirring may temporarily distribute suspended particles much like solute looks evenly distributed. 1 2
Edge cases
Colloids may look homogeneous but contain larger dispersed particles that resist settling. Concentrated or reactive mixtures may change over time, complicating a simple kitchen test. 1 2
Why the distinction exists
The classification predicts behavior such as settling, filtration, light scattering and transport through water. 1 2
Common misconceptions
A clear-looking fluid is not necessarily chemically pure. A cloudy liquid is not automatically a suspension; it may be a colloid. 1 2
Examples
Dissolved salt in water is a solution. Soil particles mixed into water form a suspension that may settle. 1 2
Sources
Sources checked October 3, 2026.
- OpenStax — Colloids. Solutions and suspensions.
- OpenStax — Phases and Classification of Matter. Elements and compounds.