Look around, and everything is a form of matter. Chemistry tells us that matter is anything that takes up physical space and has mass. We can easily apply this definition to the most common objects we encounter every day. So, the water we drink, the candy we eat, our vehicles, buildings, bodies, earth, and everything around us matter. However, earlier, this concept wasn’t that easy to demonstrate. It was hard to imagine air having a volume and mass even though it isn’t visible. Later, when scientists introduced the idea of compression of gases such that they turned liquid, they convinced people that air is a matter as well. Learn fascinating facts about the matter and the most important theories related to the nature of matter.
Although we all know the definition of matter and have a basic idea of its nature, students must note that this topic is important for those preparing for Class 12 exams, JEE, and NEET. You will find this topic in the NEET Syllabus and the JEE Main Chemistry Syllabus.
The Building Blocks of Matter
Matter is composed of very small particles invisible to the naked eye. These particles are called atoms. Earlier scientists assumed atoms to be unbreakable. However, now we know that atoms are divisible into still smaller components. So, the organisation of matter is as follows:
Characteristics of Constituents of Matter
The particles of matter: the atoms and molecules have certain characteristics that ultimately influence all substances’ nature, shape, and form.
The kinetic theory of matter explains the characteristics of constituents of matter. It states:
- Matter consists of very small particles (ions, atoms, and molecules).
- The particles are in continuous, random motion.
- The movement of particles depends on their amount of kinetic energy and the inter-particle forces of attraction.
- The kinetic energy is influenced by temperature changes, which determine the state of matter.
The main characteristics of constituents of matter are as follows:
- The Arrangement of Atoms- The Spaces Between Them
You add sugar to a glass of water, stir it, and dissolve. You see that the water remains the same. So, where did the sugar particles go? Water has some small spaces/voids in between its particles. The sugar particles go and fill up these voids. Thus, the addition and dissolution continue until all the voids are filled.
The significant space between the particles of matter is the inter-particle/ interatomic/ intermolecular space.
- The Particles Are In Continuous Motion
You add a drop of blue ink in a glass of clear water or spray perfume in a room’s corner, and the fragrance spreads all over. Why? It is due to the random motion of matter particles due to their kinetic energy. The phenomenon of mixing particles of two or more matter due to their random movement is diffusion. This random movement is also called Brownian motion (after the scientist who discovered it, Robert Brown).
The motion of particles is directly influenced by temperature rise as the increased temperature enhances their kinetic energy.
- The Attraction Between Particles
When you try to break an eraser, it is easy but breaking a pencil is comparatively harder. What makes a pencil harder? The attractive force between the constituent particles makes it hard and strong. So, the particles of different matters have different forces of attraction between them.
The interparticle/ intermolecular force of attraction and the particle’s kinetic energy play a major role in determining the states of matter.
States of Matter
Matter can take different forms depending upon the arrangement of its constituent particles/atoms/molecules. It can hold a firm shape as a solid and flows like a liquid or gas. Thus, the nature of matter can be grouped into three categories:
|Possess very strong intermolecular forces of attraction
|The attractive force is weaker than solids but stronger than gases.
|Very weak forces of attraction
|Have a definite shape
|Do not have a fixed shape and tend to take the shape of the container in which they are poured
|No fixed shape
|Molecules are tightly packed with very little or no intermolecular spaces
|Moderate intermolecular spaces present
|Large intermolecular spaces present
|Ability to compress
|Most liquids cannot be compressed easily.
|They are easily compressible.
|Vibration of particles
|The particles can vibrate only about their mean position. They cannot move.
|Particles vibrate and slide past each other.
|Particles vibrate and move freely.
|The lowest rate of diffusion
|The rate is higher than solids
|Solids can be classified into:
|Liquids can be:
|Gases can be:
You will come across several questions on nature/states of matter in NEET Previous Year Question Paper and JEE Main Previous Year Question Papers. So, students must understand the basic Chemistry concepts to nail the competitive exams.
|Did You Know?
There are some other states of matter that aren’t so common. The other states include:
Changes In The States of Matter
Haven’t you observed the different forms of water? Water changes its state depending on the available conditions. It is liquid at room temperature, solid ice at low temperatures, and gaseous steam at very high temperatures. What causes a change in the state of matter? Temperature and pressure mainly influence the states of matter as they change the forces that hold the particles together.
Solid-state → Liquid state
Why does a cube of ice melt when we place it in sunlight? There is a change of state from solid to liquid due to increased temperature. The rise in temperature increases the kinetic energy of the water molecules of ice. The molecules of ice start vibrating at higher frequencies, and the intermolecular forces of attraction decrease. Thus, water particles get separated and begin to move freely, changing their state from solid to liquid. The process of change is called melting.
Liquid state → Gaseous state
Keep a vessel of water on the flame, and you will observe steam rising from the vessel, and the amount of water in the vessel slowly reduces. When we subject liquid to an adequate amount of heat, its constituent particles begin to move at a higher speed. At a certain temperature (a boiling point fixed for all liquids), the particles gain enough energy to fight against the inter-particle forces of attraction and escape as steam (gas). This change of state of matter from liquid to gas is called evaporation.
Solid-state → Gaseous state
The naphthalene balls placed in a dry place reduce in size over time and ultimately vanish. Why? It is one of those solids that can directly convert to the gaseous state. The phenomenon is referred to as sublimation.
Gaseous state → Solid-state
Matter can also change directly from gaseous to solid-state via the deposition process. An example of deposition is frost formation.
Properties of Matter
The following table enumerates the physical and chemical properties of matter.
|Physical properties are of two types:
The attributes of matter that do not depend on the chemical composition and are observed without changing the identity of the substance are the physical properties of matter, such as
|We can study chemical properties when a matter changes or is in the process of changing its identity.
Some common chemical properties are:
Everything around us is composed of matter. Matter can take different forms depending on its internal characteristics. It is vital to understand the composition of matter of a substance to study its physical and chemical properties. Only the complete knowledge of the properties of matter/ substance can facilitate its optimal use. With an idea of what exactly matter is, NEET and JEE aspirants can effectively study NCERT Class 11 Chemistry Chapter: The States of Matter and NCERT Class 12 Chemistry Chapter: Solid State. In case of any doubt, students can refer to NCERT Solutions for Class 11 Chemistry and NCERT Solutions for Class 12 Chemistry.
1. What are the different types of matter?
The four main types of matter are as follows:
1. Solid: Substances with strong intermolecular forces and few intermolecular spaces possess a definite shape and size.
2. Liquid: Substances that take the shape of the container in which they are placed. They have weaker forces of attraction amongst particles and larger spaces between their constituents.
3. Gas: Substances with very large spaces between the constituent particles, very weak forces of attraction, and thus they lack a proper shape.
4. Plasma: A rare type of matter with very high kinetic energy particles. It is an ionised gas with almost equal positively and negatively charged particles. Stars are a type of superheated plasma.
2. Can matter be created or destroyed?
Antoine Lavoisier's law of conservation of mass states that matter cannot be created or destroyed. It can transition from one form to another via physical and chemical changes. However, even when subjected to a form change, the matter remains conserved. It will exist in the same amount before and after the change, i.e., it is neither destroyed nor created. We can also state that the total mass of reactants = the sum of masses of products + reactants that haven't reacted.
3. What is the difference between the two forms of solids?
Solid has two forms:
1. Crystalline: The atoms of crystalline solids have a definite three-dimensional arrangement. They are anisotropic, symmetrical, rigid, and have a sharp melting point. They are considered true solids.
2. Amorphous: The atoms of amorphous solids do not have a definite arrangement. They are isotropic, asymmetrical, less rigid, and do not have sharp melting points. They are also referred to as pseudo solids.
4. Are light and heat matter?
Light and heat are not forms of matter because matter is something that takes up space. While solids, liquids, and gases take up space when placed in a container, light and heat do not. Light and heat are observable, but we cannot weigh or measure them. Thus, anything that does not have a definite mass and can neither be contained in a volume cannot be a matter.