Final answer:
Compressed gases are substances in a gaseous state that have been pressurized and stored in containers. They are used in various applications and can be compressed due to the large amount of empty space between gas molecules.
Step-by-step explanation:
Compressed gases are substances in a gaseous state that have been pressurized and stored in containers. These gases are often used in various applications, such as medical oxygen for patients, compressed gas mixtures for anesthesia during surgery, compressed acetylene and oxygen mixtures for welding, and compressed propane for barbeque grills.
Gases can be compressed because they are composed of molecules that are in continuous motion and have a large amount of empty space between them. When pressure is applied, the gas molecules are forced closer together, resulting in a decrease in volume.