Phase Changes

Each material can transform into three phases: solid, liquid, or gas. Every substance is in one of these three phases at a certain temperature. The intermolecular forces acting on the material's molecules and atoms significantly impact the temperature and pressure at which the substance will change. Two phases may dwell in the same container at the same time. This usually occurs during the change from one phase to another. It's known as a two-phase condition. When the ice melts, the container contains liquid and solid water both.

Deposition

Thermal energy must be removed for a material to transition from its physical state from gas to solid; this process is called deposition. Particles in a gas have a greater quantity of kinetic or moving energy, and they vibrate at a high rate. Particles in a solid have less kinetic energy and vibrate more slowly without changing position. The reason it is termed deposition is that gaseous particles are deposited into the solid form. Gas to solid is called deposition.

Gas to Solid Examples

• To create dry ice, gaseous carbon dioxide must first be drawn out of the atmosphere. Using colder temperatures and higher pressure, the gas particles skip the liquid phase and settle into a solid to create dry ice. This is one of the deposition examples.

• Gas to solid process can be in a carbon dioxide fire extinguisher is initially filled with gaseous carbon dioxide, but the increased pressure inside the canister causes this to solidify and get expelled as a white powder when extinguishing a fire.

Condensation and Vaporisation

Condensation

When the gas is converted into liquid form by freezing or by any other method, then it is known as the condensation process.

Gas to Liquid Examples

• As the water vapour cools in the sky, clouds are created. Tiny water droplets form when the temperature of the water vapour reaches the dew point or lower. These droplets condense onto microscopic airborne dust particles to form clouds.

Vaporisation

Vaporisation is the process by which a material is transformed from its liquid or solid state into its gaseous (vapour) state. Boiling is the term for the evaporation process. Evaporation merely refers to a form of vaporisation that mostly occurs below the boiling point of water.

Liquid to Gas Examples

• The steam that rises from a hot cup of coffee is a typical illustration of evaporation. The heat escaping from the cup aids in the cooling of the coffee.

Freezing and Melting

Freezing

The process through which a material transforms from a liquid to a solid is known as freezing. When a liquid's molecules slow down enough to attract one another into permanent positions as a solid, this process is known as freezing.

Liquid to Solid Examples

• Freezing is used in food preservation techniques that involve decreasing the temperature to stop bacterial development.

Melting

Melting occurs when heat is applied, and a solid transforms into a liquid. An impure solid often melts across a range of temperatures below the melting point of the primary component, whereas this process happens in pure crystalline solids at a set temperature known as the melting point.

Solid to Liquid Examples

• Melting of steel is done to make different types of products of steel. In this process, first, the steel is converted into the molten state by heating at a high temperature and then poured into a mould for any desirable shape.

Sublimation

Sublimation is the process of changing the material from its solid to gaseous form without it being liquid, according to Physics.

Solid to Gas Examples

• Dry ice can be created by blending and freezing carbon dioxide (CO₂). At ambient temperature, this returns to its initial gaseous state.

Describe All Different Types of Phase Changes

Given below is the list of all the different types of phase changes in physics and chemistry.

1. Sublimation

Sublimation is the process where the matter changes its state from solid to gas without being converted into liquid in the first place. One of the examples of sublimation is the naphthalene balls that you use to keep your winters clothes packed and safe in summer.

2. Deposition

The opposite of sublimation is deposition, here the matter is present in the gaseous state, and as the reaction occurs, it changes into soil state without being converted into a liquid which is the intermediate state. An example of this is hard to find because you need to have a sub-zero temperature to achieve it. But in higher altitude and south and north pole, we can see vapours of water being converted into solid ice without getting into their liquid state.

3. Melting

When a matter changes its state from solid to liquid, for example, ice cubes, when taken out from the freezer, start to melt.

4. Boling

Boling of a matter occurs when it reaches a certain temperature, its a non-natural process and requires a high amount of heat. Boling water to kill bacteria inside it is also a non-natural process.

5. Freezing

When a matter changes from liquid to solid, when you put water in the freezer, and it converts into ice.

6. Condensation

When a matter changes itself from the gaseous state to liquid state, water particles in the air get condensed when they come in contact with a cold water bottle.

7. Evaporation

Changing of liquid matter into a gaseous state. The water in the ocean evaporates to form clouds in the atmosphere.

Interesting Facts

• Treatment of iodine. Iodine crystals are heated in a laboratory to produce a purple gas that has a distinctive smell.

• The melting of ghee in a frying pan.

• Snowfall and snowflakes are also examples of freezing.

Summary

Phase transitions (also known as phase changes) are the physical processes of changing from one state of a medium identified by a set of parameters to another with a set of parameters that have a different value. The phrase is frequently used to describe changes in the three fundamental states of matter: solid, liquid, and gas and, in rare instances, plasma.