Is there a relationship between gas and liquid?

Answer 1

There are a couple of ways to look at the relationship between gas and liquid. Yes, they are related, and a basic way to look at them is that a liquid is a substance that is at a temperature and pressure that allow it to exist in that state. Recall the basic physics that specifies materials as existing as a solid, liquid or gas. We also have plasma in situations where energy levels in a system are extremely high. (There are also a couple of other exotic states of matter as well.) When temperatures are low, materials are solids. Heat them and they melt or liquefy. Heat them more, and they become a gas. (Pressure plays a part here, but we can set that aside for the time being.) There is also another way that a physicist could look at a gas and liquid.

Both a liquid and a gas can be considered a fluid by an investigator. The science of fluid mechanics generally treats a liquid or a gas in the same way. Air moving across the wing of an aircraft is considered or viewed as a fluid by the engineer. Water moving across the blades of a turbine in a hydroplant is looked as a fluid by the engineering minds behind the design of the turbine. The whole of hydraulics (sometimes called fluid power by the industry) is a study in the applications of fluid mechanics.

Whether your investigations take that first step in physics and examine states of matter, or they advance to the stage where you are considering problems with moving liquids or gases, you will see connections between a gas and a liquid. A gas is the state of matter at a higher energy than that of the same material as a liquid, which is that fundamental relationship first mentioned. Additionally, a gas and a liquid could be looked as fluids by the individual making inquiries into fluid mechanics. The two states of matter (liquids and gases) behave in much the same way, and the primary difference is simply the density of the substance being considered.