Hello
The difference between the states of matter is explained as follows:
- a solid has a definite shape and a definite volume
- a liquid has a definite volume, but its shape changes depending on its container
- a gas does not have neither a definite volume nor a definite shape: both change depending on the container. In fact, a gas expands until it occupies the whole volume available.
The difference between a pure substance and a mixture is:
- a pure substance has a precise and definite chemical composition
- a mixture, instead, is a combination of two or more substances.
