It is the second-smallest county by total area in Maryland. Notable waterways include the Choptank River and Tuckahoe Creek, as well as the man-made Williston Lake. Caroline County currently ranks seventh nationally in terms of land protected under the Ag Preservation Program.
Dry air contains roughly (by volume): All the above are relatively small, light, non-polar molecules, characteristics mimicking an ideal gas. At normal ambient conditions such as standard temperature and pressure, most real gases behave qualitatively like an ideal gas.
Hydrogen, helium, ammonia, methane, neon, coal gas and pure nitrogen are all lighter than air. A pocket of air can be made lighter than the surrounding air by heating it. Continue Reading.