Hello. I'm just wondering how many cubic feet of gaseous hydrogen are in one gallon of liquid hydrogen. I know I'm not being too specific and that many variables are involved (temperature, atmospheric pressure... etc), but approximately how many are in a gallon? And yes, I have checked Google. I have found nothing useful. I wish to perform small scale experiments with hydrogen as a lifting gas in small balloons, in case you're curious. Sorry for not using metric, I'm used to U.S. Thank you!