How do you explain the properties of something we can’t see? See how scientists use scientific principles, such as gravity, to observe gases. This lesson explores gases and how we have come to know what we know about them.
Collisions between gas particles are elastic. The total amount of energy in the system remains constant. This is very hard to imagine, but we can use simple simulations and experiments to demonstrate the property. One way to do this is by dropping a soccer ball with a tennis ball balanced on top. You can calculate the energy difference and how it is transferred to the tennis ball. We can do the same thing with force carts in physics. http://www.wfu.edu/physics/demolabs/demos/1/1n/1N3030.html
When gases are mixed in a container, they each act as if they are the only gas present. In other words, oxygen molecules (O2) don’t act differently in the presence of nitrogen molecules (N2). In fact, the atmosphere is mixture of gases that you inhale and exhale every day of your life. Your body’s cells diffuse the oxygen into the bloodstream to keep the rest of your body working properly.
Every gas at the same temperature has the same average energy. But, what does that mean to particles of different sizes? Oxygen is 16x heavier than hydrogen, so how is that translated when the particles are moving? http://www.falstad.com/gas/
It’s a Gas: Math and Science of the Blimp - Gas Laws http://www.youtube.com/watch?v=hAoRKBPHpQA
If gases are always moving, can they ever come to a complete stop? How does the idea of “Absolute Zero” play into the Kinetic Molecular Theory? http://www.colorado.edu/physics/2000/bec/temperature.html
This video is of a model demonstrating how gas molecules behave: http://www.youtube.com/watch?v=jRaNw84DRnU
Gases behave differently from the other two commonly studied states of matter, solids and liquids, so we have different methods for treating and understanding how gases behave under certain conditions. http://www.shodor.org/unchem/advanced/gas/
We depend on gases every second of every day. We breathe constantly, but have you ever thought about how breathing works? Discover the ins and outs of one of our most basic living functions - from the science of respiration to how to control your breaths. http://ed.ted.com/lessons/how-breathing-works-nirvair-kaur