Gases don't have a fixed shape or a fixed volume. The particles move around all the time and spread out. This is why a gas fills its container. A gas can be compressed into a very small space – this pushes the particles closer together.

What is the shape of gas?

Gas is a state of matter that has no fixed shape and no fixed volume. Gases have lower density than other states of matter, such as solids and liquids.

Why does gas not have shape?

Gases do not have a definite shape or volume because the molecules in gases are very loosely packed, they have large intermolecular spaces and hence they move around. ... The particles of solid are closely packed and occupy less space while particles of gases are loosely packed and occupy the complete space available.