Here's why:
* Mass: Gases are made up of tiny particles (atoms or molecules). These particles have mass, even though they are very small. So, a collection of gas particles will have a measurable mass.
* Volume: Gases occupy space. They expand to fill the container they are in, taking on the shape and volume of the container. This means they have a definite volume, even though it's not fixed like a solid.
Important Note: While gases are compressible (meaning you can squeeze them into a smaller volume), they still have a volume.
Let me know if you have more questions!
