Does air has mass? This question has been asked by many. What are the responses the askers get? Some say yes, some say no, and some say I don’t know. Well in this project, I will answer the question and give you prove to all you people out there that have asked this question. Even if you never asked this question before, you get to learn something new. Before we get started, what is air? Air is the invisible gaseous substance surrounding the earth, a mixture mainly of oxygen and nitrogen but contains many other things in smaller amounts such as water vapor, argon, helium, neon, methane, krypton, ozone and carbon dioxide. The air contains a variety of tiny solid particles, such as volcanic dusts, pollen, spores of mold, bacteria, soot, finely pulverized earth and algae. Well first, you always should have a hypothesis. My hypothesis is that yes air does have mass. To answer the question, what I did was research this question and the experiments that were conducted to answer this question. I did an experiment of my own to see with my own eyes. This experiment didn’t require a lot of materials and was easy and fun. The materials needed to conduct this experiment were two balloons of equal size, a wooden ruler, something sharp like a needle, a flat surface that has an edge, and two pieces of string of equal sizes. The procedure was to place the ruler on the flat surface on the edge. I blew the balloons up to equal sizes. I attach one piece of string to the balloon and the other end the ruler. I did the same for the second balloon. I also made sure that both balloons were tied near the end of the ruler and equal distance from each other. After that, it was time to do the experiment. I puncture one of the balloons with my sharp object I picked at the beginning (which was a hand knife). I observed that after I popped one of the balloons, the ruler tipped over the surface and fell to the ground. I did this experiment a second time to be s