A troy pound is equal to 12 troy ounces and to 5,760 grains, that is exactly 373.241 7216 grams. Troy weights were used in England by jewellers. Apothecaries also used the troy pound and ounce, but added the drachms and scruples unit in the Apothecaries' system of weights.
Depends on the API gravity of the gasoline, which varies by grade and refinery. Usually, regular unleaded gasoline has a gravity of around 58 and a weight per gallon of 6.216 pounds per gallon. Premium gasoline may have a gravity of 54, or 6.350 pounds per gallon.
Helium is the lightest noble gas (4 g/mol). The only gas with a lower density than helium is hydrogen [2]. The use of hydrogen is more limited than helium because of its flammability in air mixtures. Helium (0.179 g/L) is 86% less dense than room air (1.293 g/L) and 8 times less dense than oxygen (1.429 g/L) (Figure 1).