What is the least dense gas?

Answer 1

Aerogel is a manufactured material with the lowest known density of any solid. It is derived from a gel in which the liquid component of the gel has been replaced with a gas. The result is an extremely low-density solid with several remarkable properties, most notably its effectiveness as a thermal insulator and its extremely low density. It is nicknamed frozen smoke, solid smoke or blue smoke due to its translucent nature and the way light scatters in the material; however, it feels like expanded polystyrene (styrofoam) to the touch.

Aerogels are produced by extracting the liquid component of a gel through supercritical drying. This allows the liquid to be slowly drawn off without causing the solid matrix in the gel to collapse from capillary action, as would happen with conventional evaporation. The first aerogels were produced from silica gels. Kistler's later work involved aerogels based on alumina, chromia and tin oxide. Carbon aerogels were first developed in the late 1980s.

Answer 2

The least dense liquid would be found at the top.

Answer 3

Water only has one density: 1 gram per centimeter cubed.

Answer 4

rubbing alcohol

Answer 5

Hydrogen

Answer 6

water vapor