Solids, liquids, and gases are the three states of matter. They are made of atoms, molecules, and/or ions. The behaviors of these particles in solids, liquids, and gases differ from each other. Solids retain a fixed shape and volume. They are not easily compressible and do not flow easily. Liquids assume the shape of the container and have constant volume. They are not easily compressible since particles are close to each other. The gas assumes the shape and volume of its container. The behavior of gases is compressible since the particles are widely spaced.

This article, let us know the behavior of gas and also discuss the ideal gas law. The presence of wide space between the gas particles makes them move easily and we can witness that gas possesses more kinetic energy. We can clearly observe that the particles in a gas move very rapidly and collide with each other. This causes gas molecules to spread out or to diffuse throughout the volume of the container until they are evenly distributed.

## Pressure Creation by Gas

When the gas enters the container, the particles in the gas move rapidly inside the container. Since the container has a fixed volume and shape, the gas molecules cannot have wide spaces between them and cannot spread out easily. This makes gas to be compressed. The particles of the gas exert great force on the interior volume of the container and this force is referred to as pressure. Other measurable properties of gas include a number of particles which is expressed in a mole number, temperature (T) measured in Kelvin scale, and volume (V). Let us know about the ideal gas law which is also known as the general gas equation that states the behavior of gases clearly. The ideal gas law is derived from the observational work of Gay-Lussac, Robert Boyle, and Amedeo Avogadro.

The ideal gas law states that “the product of the pressure and the volume of one gram molecule of an ideal gas is equal to the product of the absolute temperature of the gas and the universal gas constant.”

The ideal gas law is given by the equation PV=nRT.

## The Behavior of Light

Let discuss the behavior of light and also discuss the famous law – Snell’s law that explains the behavior of light much more clearly. Light is the form of electromagnetic radiation and is a form of energy. The Sun is the main source of light on the Earth. It is one form of energy visible to the human eye. Light has the ability to undergo various phenomena like reflection, refraction, diffraction, and interference. When a ray of light strikes a smooth polished surface, the light ray bounces back, this phenomenon is known as a reflection of light. The laws of reflection determine the reflection of incident light rays on various surfaces. Refraction is defined as the change in the direction of light waves when they move from one medium to another. The law of refraction is also known as Snell’s law.

Snell’s law is also known as Snell–Descartes law, it was put forth by Willebrord Snell in 1621. Snell’s law states that “The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant, for the light of a given color and for the given pair of media”.

Snell’s law is given by the formula n1 sin θ1 = n2 sin θ2

Where n1 and n2 are the indexes of refraction of the first and second media.

Sin i / Sin r = Constant

The refractive index for a medium is represented by n and is given by the formula. Refractive index is  n=c/v

Where: c=speed of light in a vacuum and v= the speed of light in the medium.

Note: Refractive Index is a dimensionless quantity.

Hope you have understood Snell’s law and ideal gas law in detail in this article.