Posted by: Green Knight | February 1, 2012

Weighty Matters

Wow, when I posted the challenge about how much air weighs, 53 days ago, I got virtually no reaction, but yesterday I had 31 hits on it. Some science teacher must have assigned it to a class, or something. I still haven’t had any answers, though. You must first consider what our troposphere is composed of, then figure out the ratios of the gases. You don’t even have to factor in Boyle’s law or Dalton’s law, just molecular and atomic weights. The first right answer wins a glass of dihydrogen monoxide.

(image courtesy of the movie “Air,” found at take a deep breath and watch it.)



  1. OK, I know my answer will probably be wrong, but here is some interesting info that I found:
    “The total weight of the atmosphere exerts a pressure of about 14.7 pounds per square inch at sea level. You don’t notice this weight, however, because you are used to it. If you live in Denver, Colorado, which is at an elevation of about 5,000 feet, then about 85% of the atmosphere is above you, resulting in an air pressure of about 12.5 pounds per square inch. At the top of Mount Everest (over 29,000 feet), only 30% of the atmosphere lies above you, leaving an air pressure of only 4.4 pounds per square inch.”

    Don’t blame me if the answer is wrong, I got it off the following weather site!

  2. LOL, that’s air pressure, but good job, gracious radio hostess! I was looking for molecular weight. If i get to speak at the SEJ conference in October, this might be one of my pre-lecture quiz questions. Let them be warned.
    Also, the lesser air pressure at great heights, like on Everest, makes a climber a bit puffy, and causes altitude sickness. I tried to climb Mt. Whitney in one day back in the early ’70s. The more rational thing to do is go halfway up and make camp for the night.

  3. Gulp…at least I tried, eh prof?

  4. well, my neighbor Kelly got it right. free glass of water whenever he wants it. the answer is 28.97. you just need to look at your periodic table. 78% nitrogen as N2, 20.95 % oxygen as O2, !% monatomic argon, about 390 parts per million CO2, and some trace stuff.

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