Hi. So, it's been awhile. Before you read any further, I just wanted to say that this is a science-heavy post. I will be using technical terminology, which I have attempted to explain, but if you're not all that into science or don't want to hear a whole lot about temperature scales and states of matter, you might want to skip this one.
Anyway. Today my chemistry lecture started the subject of gases and gas laws, so my instructor (who, sadly, is a temporary one who is leaving after this Friday to be replaced by the person who was originally supposed to teach this class) did a demo showing what happens when a balloon is cooled rapidly. (Obviously I understood the gas law stuff VERY well.) And she showed some other cool stuff that had nothing to do with what we were covering but it was AWESOME so whatever.
Anyway, she started with 3 balloons and did the same thing with each one in succession. These balloons were not filled with helium, though. They were filled with oxygen. I'm going to assume anybody reading this knows what oxygen is, and if you don't, bless your heart and go Google it. For those not in the know, it is possible for oxygen to exist in a solid and liquid state as well as the typical gaseous state, but it has to be very, very, VERY cold. To explain how cold it is, I have to explain absolute zero and the Kelvin temperature scale and how it relates to Celsius and Fahrenheit.
Absolute zero is a theoretical temperature (I think it's been done in laboratory conditions) at which all molecular movement stops. What I mean by this is that when water freezes, the molecules are in a solid formation, but they are still vibrating. Not so with absolute zero. Absolute zero is typically used along with the Kelvin temperature scale. The degrees of the Kelvin scale are the same size as the degrees on the Celsius scale, so going up 1 on the Kelvin scale is just adding 1 to the converted number on Celsius. 0 K is absolute zero. That is -273.15 degrees Celsius, or -459.67 on the Fahrenheit scale. That is unfathomably cold. Anyway, if the temperature on the Kelvin scale was 1 K (degrees are not used in the Kelvin scale), the temperature on the Celsius scale would be -272.15 degrees Celsius. Conversely, 0 degrees Celsius is 273.15 K, and 1 degree Celsius is 274.15 K. I think I've made my point.
Oxygen exists as a gas at room temperature (22 degrees Celsius is considered standard room temperature, it's about 72 degrees Fahrenheit), that is something that is taken for granted. The freezing point of oxygen is 54.36 K (-222.65 degrees C), and the boiling point is 90.19 K (-182.96 degrees C). This means oxygen exists as a liquid between 54.36 K and 90.19 K. In case you haven't caught on, that is VERY VERY VERY cold. On this planet, oxygen cannot exist as a liquid or a solid except in laboratory settings. I saw liquid oxygen with my own eyes today.
So, back to the oxygen balloons, which, by the way, do not float! How cool is that? Pure oxygen is heavier than air, since air is about 78% nitrogen, which has a lower atomic weight than oxygen. (Oxygen only makes up about 21% of our atmosphere.) Anyway, she took a balloon and placed it on a table at the front of the room, then grabbed a jug of liquid nitrogen (exists as a liquid between 63.15 K (-210.00 degrees C) and 77.355 K (-195.795 degrees C)), poured some into a styrofoam cup, and then took that and poured it over the balloon, which shrank dramatically before our eyes, because the volume of the gas inside of it had decreased with a decrease in temperature. They didn't put anything to catch the nitrogen, either, so it beaded, rolled off the table, and sizzled and steamed as it fell to the carpet, where it made very solid plopping noises as it boiled its way back to vapor. Coolest thing I have ever seen, I could have watched her do that all day. Anyway, she very quickly cut the balloon open, and poured the condensed (liquid) oxygen into a beaker to show us. It was boiling and sizzling. Apparently it is paramagnetic, which I didn't fully understand, but it followed a magnet she ran along the underside of the container and even stuck to it (sizzling and boiling the whole time) when she dunked the magnet in there. AND IT IS PALE BLUE. How cool is that?!
Anyway, she did that twice more, only she dunked cotton balls in the liquid oxygen this time and set them on fire. They sparked like sparklers on steroids. Seriously, this was one of the coolest things I've ever seen in my life.
As an aside, I'm pretty sure things like metals can also exist as a vapor. Silver, for instance. Silver is kind of the same thing as ice - all ice is is solid water, it's a state of being. The point at which silver becomes a liquid is 961.93 degrees C (1763.474 degrees F), and the point at which it boils (in other words, becomes a GAS) is 2212.0 degrees C (4013.6 degrees F). Silver can exist as a vapor. (For reference, the sun's surface temperature is 5504.85 degrees C or 9940.73 degrees F.) So for silver to exist as a vapor, it would have to be about half the temperature of the sun's surface (the core of the sun is 15.7 million K). That's pretty hot. BUT IT COULD HAPPEN. Somewhere out there in this big, big universe, there is a place where silver exists as a vapor. Hell, there could be a place with beings living on it that BREATHE silver.
Anyway, I've pretty much exhausted my science excitement for tonight. I needed to share this whole thing with liquid oxygen, though. Because seriously, that was cool as hell. (I'm not changing my major, though. I would be a horrible chemist.)
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