Each phase of matter has its own chemical and physical properties. The phases of matter you need to know are:
- Solid - a solid has a definite shape and volume
- Liquid - a liquid has a definite volume, but can change shape
- Gas - the shape and volume of a gas can change
Phase Changes
These phases of matter can change from one to another. Remember the definitions of the following phase changes:
- Melting - melting occurs when a substance changes from a solid to a liquid
- Boiling - boiling is when a substance changes from a liquid to a gas
- Condensing - condensation is when a gas changes to a liquid
- Freezing - freezing is when a liquid changes to a solid
The changes that take place in substances may be categorized in two classes:
- Physical Change - does not produce a new substance (e.g., phase changes, crushing a can)
- Chemical Change - produces a new substance (e.g., burning, rusting, photosynthesis)
Solutions
A solution results from combining two or more substances. Making a solution can produce either a physical or chemical change. You can tell them apart this way:
- The original substances can be separated from one another if the solution produces only a physical change.
- The original substances cannot be separated from one another if a chemical change took place.
Learn about chemical reactions...


