Chemistry is a study that has existed since ancient times. Over this time frame, it has evolved, and now chemistry encompasses various areas of specialization, or subdisciplines, that continue to increase in number and interrelate to create further interdisciplinary fields of study. The applications of various fields of chemistry are used frequently for economic purposes in the chemical industry.

As discovered by scientists,

The matter is made up of very tiny particles and these particles are so small that we cannot see them with naked eyes.

It has been observed that matter exists in nature in different forms. Some substances are rigid and have a fixed shape like wood and stone; some substances can flow and take the shape of their container like water, while there are forms of matter that do not have definite shape or size such as air.

Matter can be classified into different categories based on the physical properties exhibited by them and the states in which they exist; these are called states of matter.

Following are the basic three states of matter:

• Solid

• Liquid

• Gas

Apart from the above mentioned three, there are 2 more states of matter which we do not see in our everyday life. They are Plasma & Bose-einstein condensate.

Changes in the characteristics of matter related with external influences such as pressure and temperature separate states of matter. A discontinuity in one of those qualities frequently distinguishes states: rising the temperature of ice, for example, generates a discontinuity at 0 °C (32 °F) as energy flows into a phase transition rather than temperature rise.

A solid is a state of matter that retains its shape and density when not confined.

What is a solid state?

When particles are arranged and packed closely compared to those in a gas or liquid and are relatively stable, they are considered to be in a solid state. Solids tend to have a rigid shape, as the atoms or molecules of matter in the solid state are generally compressed and tightly connected through chemical bonds. These bonds can produce an amorphous shape or a regular lattice. In electronics, solid state refers to components and systems based entirely on semiconductor materials, such as silicon, germanium or gallium arsenide. Transistors and diodes the most common solid-state devices are often combined with resistors, capacitors and other components to create integrated circuits (ICs). All electronic systems incorporate ICs and, therefore, transistors. A solid can be defined as a substance which exists in the solid-state, which is one of the four fundamental states of matter. Solids feature closely packed atoms whose kinetic energies are much lower than those of liquids and gases.

Examples of Liquids

At room temperature, examples of liquids include water, mercury, vegetable oil, ethanol. Mercury is the only metallic element that is a liquid at room temperature, although francium, cesium, gallium, and rubidium liquefy at slightly elevated temperatures. Aside from mercury, the only liquid element at room temperature is bromine. The most abundant liquid on Earth is water.

Properties of Liquids

While the chemical composition of liquids may be very different from each other, the state of matter is characterized by certain properties:

• Liquids are nearly incompressible fluids. In other words, even under pressure, their value only decreases slightly.

• The density of a liquid is affected by pressure, but generally, the change in density is small. The density of a liquid sample is fairly constant throughout. The density of a liquid is higher than that of its gas and usually lower than that of its solid form.

• Liquids, like gases, take the shape of their container. However, a liquid cannot disperse to fill a container (which is a property of a gas).

• Liquids have surface tension, which leads to wetting.

• Although liquids are common on Earth, this state of matter is relatively rare in the universe because liquids only exist over a narrow temperature and pressure range. Most matter consists of gases and plasma.

• Particles in a liquid have greater freedom of movement than in a solid.

• When two liquids are placed into the same container, they may either mix (be miscible) or not (be immiscible). Examples of two miscible liquids are water and ethanol. Oil and water are immiscible liquids.

Gas is the state of matter in which the particles are far apart, fast-moving and not organised in any particular way.

• Gases are substances that exist in the gaseous state, which is one of the three fundamental states of matter. 

• Gases are highly compressible and feature very large intermolecular distances.

• The gaseous state features very small attractive forces between the gas particles, which are separated from each other by relatively greater distances when compared to liquids and solids.

•  It is important to note that substances that exist in the gaseous state do not have any definite volume or any definite shape. 

• They tend to occupy the entire volume of the container they are placed in.

•  Furthermore, gases are highly compressible and are known to exert some finite pressure on the walls of their containers.