[Physics Class Notes] on Matter Pdf for Exam

Introduction to Matter

Many of you have seen the change in the state of matter. For example, you must have seen the melting of ice cubes into the water. What is the change in phase here? The ice is converted into water that means it changes from a solid to a liquid state. Why does this happen? 

Here, we notice the change in states of matter. The boiling of water helps it to turn into vapour form. This is also a change in states of matter. In this article, we will know about many terms and formulas that are associated with the states of matter and their properties.

Properties of Matter

A substance changes its form (change in the state of that matter) when it gains a massive amount of energy. Due to energy absorption, the atoms and molecules start to move rapidly. The random movement of atoms and molecules results in the deformation of the molecular structure of the matter.

Types of Matter

When you read this article, the first thing you notice is about the three states of matter. How do you know the states? Well, here is the solution. 

When you notice a physical change in the matter, you can call it has changed its state. It transforms from one form to another. Change in the state of matter is reversible in many cases. However, chemical changes do not include reversible categories. 

The figure given below will show you the changing states of matter:

You must have heard of some common changes of state such as freezing, melting, deposition, sublimation, condensation, and vaporization. Well, these changes are the paths that lead to change in states of matter.

All of the changes satisfy one law, i.e., the Law of Conservation of Matter.  

Change Between the State of Solids and Liquids

Have you made some ice cubes by keeping them in a tray? If you have done this earlier, you can learn easily. But don’t worry. Here we provide you with a complete package of knowledge. 

When you put a tray full of water into a refrigerator, you will notice that they would have converted into ice after some time. This is called freezing. If you keep them on the same steel tray and supply heat, it will turn into the water once again.

Now let’s know why this behaviour is found among different matters, along with the examples of matter.

1. Freezing

When you keep the tray inside the freezer, the water comes into the interaction with the cold air inside the freezer. This helps the water to drop its temperature by keeping the molecules’ energy level to none. Water molecules do not have sufficient energy to collide with each other, and they turn into ice afterwards. 

The point at which a temperature is responsible for turning the water into ice is called the freezing point.

2. Melting Point

When put out of the freezer, it would have hardened. Now, if you apply the heat to initiate the change in the state of the molecules, they will start melting. This is because they absorb the heat energy provided via the tray.

The force of attraction between water molecules will exist no more when the temperature reaches a certain point. The point at which the entire ice cubes convert into water is known as the melting point.

Changes Between the State of Liquids and Gases

1. Vaporization

This is the phase where extreme heat supply helps the water to turn into vapour form. The force of attraction between molecules will fail at this stage.

2. Condensation 

When water vapour interacts with something, cooler surfaces, such as the plane of a mirror or any steel tray, some portion of the vapour will stay on its surface due to temperature difference. They stay in the form of water droplets. This is called condensation.

Changes Between the State of Gases and Solids

We know this phase as sublimation when the solid substances will pass directly to the vapour phase by skipping the liquid phase.