 So that's solids and monatomic gases. How about molecule gases? Well, here's a CO2 molecule. And what we're doing here is applying an autodetic electric field. This is what happens when light falls on carbon dioxide or some molecule. The light is an electromagnetic wave, which means it's got an oscillating electric field. Electric field pulls a positive charge one way, the negative charge the other way. And because of the bonding in here, the positive negative charge is what the opposite ends. And it sets the whole thing vibrating. So if you have something like carbon dioxide, it can have some energy as a carbon dioxide molecules move around, but it can also have energy as they vibrate like this. Or for that matter, if you apply a faster electromagnetic wave to it, you can get different oscillations. This time it's resonating another way and the center is moving backwards and forwards in this direction. And so you can also have energy in that form. Something like a water molecule. This has even more exciting things happen when you apply an electric field to it, like light, because the charges are not all lined up. You have the oxygen in the middle and the hydrogen on the outside. And so in this case, if you're applying radiation to it, like sunlight falling on some water, it can do all sorts of cool things. It can vibrate and rotate. So in general, if you have a monatomic thing, just single molecules, then all that's gonna happen is they'll move and so the heat that we just need to get there can take energy increased. If you have a solid, you're going to have to put some energy in to make the move and also some energy to make the springs stretch and unstretch. If you have a molecule that's free to rotate, you'll also have some energy coming in rotation, spinning and vibration of the modes. So these are all forms of energy that you can put into things.