Learn about Senior Chemistry, Energetics 4, in this comprehensive video by bannanaiscool.
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There are two main types of energies that we are going to consider and they are very important to us of course. And those are kinetic energy and potential energy. We can break those down and really get into them now at the senior level. Kinetic energy as you know is the energy of movement or the energy of motion. Now, let’s bring that right down to the molecular level. How can this molecule express kinetic energy? Absorb it or release it? Well, there are three different ways that we can do eK—Kinetic energy. The first way that a molecule can actually absorb energy is by actually moving back and forth along the length of the bond. And a bond remember is just a force of attraction between atoms. There’s no real stick in between atoms, there is just a bond—force of attraction. Now, that bond length can be altered by atoms actually coming closer together moving farther apart. A bond like this never really rigid, but it actually fluctuates because of the amount of energy that could be in tremor or leaving this system. And so, we call that because there is vibrating along that bond length, vibrational energy. So that’s the first type of kinetic energy. But then if you continue to apply energy to this molecule not only will it vibrate, but it can actually move around its bond length. And so, not just vibrating but also rotating and so the second type of energy is called rotational energy. So there is vibrational and rotational but then you can take molecules and even move them around the place. And when you do that that’s going to be translational—trans of course means across. So you're moving it across somewhere. So there is vibrational, rotational and translational. Now what would really exhibit a higher degree of vibrational energy than any of the others? Well that will be like a solid. Anything that’s solid would have some vibrational energy between the molecules. This table, this body is solid but the molecules in me are constantly having their atoms moving back and forth they're vibrating. The only time you wouldn’t have that is an absolute zero. Zero K. Negative 273.15 degrees Celsius. So here we’ve got a molecule that vibrates—that’s like solid. Now what about liquids? Well liquids they do vibrate but they also have the ability to move about in solution like this so they rotate. And then of course a gas, think of how chaotic a gas is. It will vibrate, have molecules as well, it will rotate and they can move from place to place.