Gas is in a stable state at room temperature, whereas a vapor is a substance which is in a gaseous and liquid equilibrium at room temperature, at a specified pressure. Gas can also involve a single element of matter with its own unique physical and chemical properties.
Vapor is the gaseous state of an element. Vapor particles are a single element and may have a fixed shape. Gas particles do not have a fixed form and are a collection of atoms, ions, electrons, and molecules. However, both gas and vapor particles are in random motion, colliding with each other or the walls of the encompassing vessel when observed under a microscope.
Gas is known to be one of the main states of matter. It is usually not seen, but some varieties can be smelled. It can remain in the same state when it is in room temperature while vapor is usually a mixture of two substances and may have a reaction when it is placed in different temperatures.
Vapor is usually a mixture of both liquid and gas while the gas will only contain gas. If the gas would be mixed with other gases, then its state will still be gas. One example of gas is hydrogen, but if you would mix it with oxygen, it will become water, which means that water is a vapor.
E. Barnes, Professional Gamer, Professional Gamer, Washington
Answered May 24, 2019
At room temperature, a gas is just one defined state, while vapor is a substance that has gaseous and liquid equilibrium, due to experiencing a phase change. Gas is also known for being a single element of matter. This element has its own defining chemical and physical properties. Examples of these gases include neo and oxygen. Vapor is the element's gaseous state.
While they have a definite shape, gas particles don't. Instead, they are a collection of atoms, molecules, and electrons. Gas produces when the temperatures kinetic energy is too high to stay a liquid, while vapor is produced from the pressure of a substance.