Gases are a state of matter which may or may not be seen by the human eye. They can be made from individual atoms or a variety of atoms. Atoms are tiny bits of electricity made up of protons neutrons and electrons. Properties of Gases: 1. Gases expand to fill containers they are in. 2. Gases are easily compressed or squished. 3. Gases take up more space than the solid or liquid they came from. 4. Gases have no definite shape or volume of their own.