In brief The most efficient shape for withstanding high pressure is a sphere but that would be costly to manufacture. A cylinder with a domed top and a domed bottom (look underneath, the flat base is actually welded around the outside, the bottom of the gas container is actually domed) is a much cheaper shape to manufacture whilst still having good stength to resist the internal gas pressure.
Some other ideas
The idea that "cylindrical vessels have minimum surface area to volume ratio and thus reduces heat transfer" is incorrect. The surface area to volume ratio for a cylinder depends on the ratio of its length to its diameter and most cycinders are manufactured with a much greater length than is ideal for minimising surface area. In fact a cube would be a better shape than most gas cylinders if this was the primary design consideration. Also heat transfer is actually often a good thing for gas containers, liquids require heat to convert to gases. Try using a butane cylinder on a near freezing day......
The idea that "they are cylindrical because there are no weak points such as joins and corners that the gas molecules could force apart" is partially correct, a cylinder with hemisperical ends has no corners which would certainly act as stress concentrators and therefore be much weaker for the same material thickness but many low to mid pressure gas containers are welded from sheet material so there are joins.
Superfluidity
Superfluidity
no definite shape but a definite volume - :DD
Yes, particles in a gas will fill the available space of their container and take on the shape of the container. The volume of the container doesn't affect this behavior as the particles will distribute evenly throughout the space.
A gas will expand to fill up any volume available to it. Think of rigid containers that will not change shape or volume. If you have 10 completely empty containers that can be connected. Inside each is a vacuum. Place some gas in the first container. It completely fills the container and creates some pressure. Connect a second container and some of the gas leaves the first container, but not all of the gas. The gas will completely fill both containers, but creating less pressure. Continue connecting containers, and the same appens every time. The gas completely fills every container that is connected and the pressure 'adjusts' on its own to reach a new equilibrium pressure.
Simply because - the shape allows the contents to exert even pressure throughout the vessel.
Most fire extinguishers contain a powder with a pressurized propellant, or sometimes just a pressurized gas, and occasionally a liquid under pressure.Round containers are best for pressurized containers because they retain their shape under pressure. Most fire extinguishers are cylindrical shaped with either concave or convex ends.
Solids. (Anything that isn't a liquid or a gas)
Superfluidity
A gas-collecting tube is made of glass and has a cylinder shape with a valve at one end of the cylinder. Most gas-collecting containers have a gauged volume on them. They are used in science for the purpose of taking samples of a gas.
takes shape of its containerThey both flow and have shapes defined by their containers.
A teardrop is the most aerodynamically effective shape for a rocket travelling through the atmosphere. From an engineering standpoint, a cylindrical shape accommodates compressed gas cylinders (fuel and oxygen) most efficiently. For a rocket operating outside the atmosphere, shape is irrelevant because it will not encounter drag no matter how un-aerodynamic the shape.
The common states are gas and liquid.
The state is gas. Gasses can expand and be put in containers of different shapes.
A gas changes shape when placed into a container. Gases do not have a fixed shape or volume, and they expand to fill the space available to them. This is in contrast to solids and liquids, which have a fixed shape and volume.
Liquid and gas can flow and change shape to fit their containers, while solids have a fixed shape and volume. Liquids and gases can also be easily compressed or expanded, which is difficult for solids to do.
Superfluidity