Classification of Matter: Elements, Compounds, Mixtures

Classification of Matter: Sugar, salt, ornaments, clothes, hair, chair, utensils, and various other things around us are made up of matter. We can feel these things through our senses. Thus, we can define matter as anything that has mass and occupies space, but have you ever wondered whether all these substances are similar or different. This article will help you explore more about the classification of matter in detail based on its properties and applications.

Classification of Matter and Its Importance

Classification means grouping things together based on similar features and properties. It is advantageous as it makes the study of substances around us much more accessible. Furthermore, it helps to understand and study the characteristics, similarities, and differences among different matters and how can they be grouped under separate categories. Let us know more through the classification of matter examples.

Classification of Matter Based on Physical States or Kinetic Theory

There are three physical states of matter- Solids, Liquids and Gas.

The properties that decide the state of the substance are:

1. Inter-particle space,
2. Force of attraction between particles, and
3. The kinetic energy of particles due to their motion

Let us study about each physical state-

Solid State

The particles of solids are very closely packed and have a strong force of attraction between them. This strong force of attraction holds the particles together in fixed positions.

Ice, wood, rock, coal, bricks, etc., are some common examples of solids. The solids have the following characteristics-

1. Solids have fixed shape and fixed volume.
2. Solids cannot be compressed much.
3. Solids have a high density, and thus, they are heavy.
4. Solids do not fill their container completely.
5. Solids do not flow.
6. Solids have high melting and boiling point due to strong forces between constituent particles.

Exceptions

1. Rubber stretches on applying force and can regain shape when the force is removed.

2. A sponge can easily be compressed, as it has tiny pores in which air is trapped.

Liquid State

The particles of liquids are less closely packed, and the force of attraction between the particles is less than solids. The force is not strong enough to hold the particles together in a fixed position.

Water, alcohol, oil and milk are some examples of liquids. The liquids have the following characteristics-

1. Liquids have a fixed volume but no fixed shape.
2. They take the shape of the vessel in which they are kept.
3. Liquids cannot be compressed much.
4. Liquids have moderate to high densities. They are usually less dense than solids.
5. The particles of liquids do not fill the container completely.
6. Liquids flow easily.

Gaseous State

The particle of gases are far from each other, and the force of attraction between the particles is negligible. Due to this, the particles have no fixed position and are constantly moving.

Air, oxygen, nitrogen, hydrogen, methane, etc., are some examples of gases. Some characteristics of gases are-

1. Gases neither have a fixed shape nor a fixed volume.
2. Gases are highly compressible.
3. Gases have low densities.
4. Gases can flow.
5. Gas fills the container completely.
6. Gases can diffuse.
7. Gases exert pressure.

Thus, we can summarise the state of matter through the following table. This classification of matter chart will help in revising the properties quickly.

In recent discoveries, two new states have been seen. One is called plasma, and another is Bose-Einstein Condensate (BEC), and they have properties different from the three states of matter.

Plasma

Plasma is a mixture of electrons and ions. The state involves active and energized atoms in the form of ionized gases. It is usually

created by heating a gas until it loses all its electrons. This state is existent in stars and the sun because of very high temperature.

Bose-Einstein Condensate (BEC)

In \(1920\) an Indian scientist Satyendra Nath Bose did some calculations on the fifth state of matter. Later, Albert Einstein predicted the existence of this state.

This state refers to the breakdown of atoms in a single quantum state. The state is found at low temperatures and can be created byzing a gas of tremendously low density.

Classification of Matter Based on Chemical Properties

Matter around us is not pure and chemically can be classified as Pure substances and Mixtures.

Pure Substances

A pure substance is made only of one kind of particle. These particles can be atoms or molecules. A pure substance is either an element or a compound.

Element

An element is a pure substance composed of only one kind of atom.

Characteristics of an Element

1. Each element consists of only one kind of atoms. Therefore, no two elements can have the same type of atom.
2. An element is composed either of an individual atom or molecules made of this atom.
3. It has its own fixed melting and boiling points.
4. An element cannot be broken down into simpler substances by any physical or chemical means.
5. An element may chemically react with another element or compound.

Based on their properties, elements can be further classified as:

1. Metals
2. Non-metals
3. Metalloids
4. Noble gases

Metals

The characteristics of metals are:

1. They are hard solids.
2. They are lustrous. 
3. They are good conductors of heat and electricity.
4. They are ductile, i.e., they can be drawn into wires.
5. They are malleable, i.e., they can be hammered into sheets.
6. They have high melting and boiling points.
7. They are sonorous.

Some examples are- Gold, iron, silver, platinum, mercury, etc.

Non-metals

The characteristics of non-metals are-

1. They exist in all three physical states- solids, liquids and gas.
2. They are not lustrous. 
3. They are bad conductors of heat and electricity.
4. They are neither ductile nor malleable.
5. They are brittle.
6. They have low melting and boiling points.
7. They are not sonorous.

Some examples are- Carbon, phosphorus, oxygen, sulphur, etc.

Metalloids

They are elements that show the properties of both metals and non-metals.

Examples are arsenic, germanium, bismuth, etc.

Noble Gases

Helium, neon, argon, krypton, xenon, and radon are chemically inactive or inert elements. They occur in the state or traces in the atmosphere and have monoatomic molecules. They are also called rare gases.

Compounds

A compound is composed of two or more elements, combined chemically in a fixed proportion by mass. It cannot be separated by physical means.

Characteristics of Compounds

1. A compound contains atoms of two elements combined chemically.
2. All samples of a compound have identical physical and chemical properties.
3. The elements in compounds are present in a fixed ratio by mass.
4. The properties of compounds are different from those of their constituent elements.
5. The separation of a compound into its constituent elements is possible only by chemical means.
6. Energy is neither liberated nor absorbed during the formation of compounds.
7. A compound has its characteristic melting and boiling points.

Some examples of compounds are- water, carbon dioxide, nitrogen dioxide, etc.

Mixtures

A mixture may be defined as a matter composed of two or more substances whose particles are in contact. However, they have neither combined chemically nor have they lost their individual properties.

Characteristics of Mixtures

1. A mixture consists of two or more substances that exist together without any chemical force acting on them.
2. It can have its components in varying proportions.
3. Physical methods can separate the components of a mixture.
4. The melting and boiling points in mixtures are not fixed. Instead, they depend on the proportions of the constituents particles.
5. Usually, no energy change is observed during the formation of mixtures.
6. Mixtures may exist in any states of matter.

Depending on the composition of particles, mixtures can be classified as

Homogeneous mixture and Heterogeneous mixture.

Homogeneous Mixtures

Those mixtures in which the substance are thoroughly mixed together and indistinguishable are called homogeneous mixtures.
A homogeneous mixture has a uniform composition throughout its mass.
It has no visible boundary of separation between various constituents.
All homogeneous mixtures are called solutions.

Some examples are- sugar solution, salt solution, alcohol and water, soda water, etc.

Heterogeneous Mixtures

Those mixtures in which the substance remains separate and one substance is spread throughout the other substances as small particles, bubbles, or droplets. A heterogeneous mixture has non-uniform composition throughout its mass.
It has a visible boundary of separation between various constituents.

Some examples are- sugar and sand mixture, salt and sand mixture, starch solution, soap solution, muddy water, etc.

Summary

This article discussed the classification of matter on its physical state or chemical properties. We also studied about two new states of matter- Plasma and Bose-Einstein condensate. Matter can be broadly classified into solids, liquids, and gases on the basis of their state. Based on their chemical properties, matters can be classified into Elements, Compounds and Mixtures.

FAQs on Classification of Matter

Q1. What are the five classifications of matter?
Ans: The five classifications of matter according to its physical state are- Solids, Liquids, Gases, Plasma, and Bose-Einstein condensate.

Q2. What is the classification of matter and examples?
Ans: Classification means grouping things together based on their similar features and properties.  It is advantageous as it makes the study of substances around us much more accessible. It also helps to understand and study the characteristics, similarities, and differences among different matters and how can they be grouped under separate categories.
For example, a matter can be classified according to its physical state- Solids, liquids, and gas. It can also be classified according to its chemical properties as pure substances and mixtures.

Q3. What are the three states of matter?
Ans: The three states of matter are solids, liquids, and gas.

Q4. How do we classify mixtures?
Ans: Mixtures can be classified as homogeneous mixtures and heterogeneous mixtures.

Q5. What is the physical classification of matter?
Ans: The properties that decide the physical state of the substance are:
(i) Inter-particle space,
(ii) Force of attraction between particles, and
(iii) The kinetic energy of particles due to their motion