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Gases are defined as substances generally found in the gaseous state. They are largely compressible and feature intermolecular distances. As compared to solids and liquids, the gas particles are at larger distances from one another. Note the gas substance does not have any fixed shape, size, or volume. However, they occupy the space they enter. Today, in this study material notes on Properties of Gases, we will talk about gases in general, gaseous state and Properties of gases in detail, and other related topics. So, without any further ado, let’s get started with Properties of Gases study material.  

What is Gas? 

Gas is referred to as a state in which the particles are not packed closely; on the contrary, they are far apart, unorganised, and fast-moving compared to another state such as liquid or solids. They are readily present in the gaseous state, one of the states of matter out of the three states. In between the gas particles, this state features the least attractive forces separated with larger distances. Note the gas does not have any definite shape or definite volume whereas, it takes the shape of the container it is occupied in.  

Introduction to the Gaseous State 

The matter is the building block of living organisms. The water we drink, the air we breathe, or the pencil we use for writing is all in the form of matter commonly known as gas. Imagine a minute without air? Impossible, right? Humans, as well as all living organisms, are dependent on air, a gaseous state of matter. Hence, it is referred to as the building block of life. 

The atmosphere we live in is a mixture of several gases, including oxygen, carbon dioxide, nitrogen, ozone, water vapour, and so on. Compared to other states, the gaseous state is referred to as the simplest state. It is important to note that, in the periodic table, there are only eleven gases that act or behave like gases. These include Argon, Krypton, Helium, Neon, Hydrogen, Xenon, Radon, Nitrogen, Fluorine, Oxygen and Chlorine. Another name for these gases is “Pure gas.” 

Here are the primary differences between solid, gas, and liquid. Let’s have a look- 

  • Solids have a definite size, shape and volume. 
  • Liquids do not have a definite size or shape; however, they can occupy a fixed volume. 
  • Gases do not have a definite size, shape and or even volume. However, they are extremely compressible. 

Properties of Gases 

As discussed earlier, Gases do not have a definite size, shape and or even volume. However, they are extremely compressible. The room you’re sitting in is full of gas, or the atmosphere you’re breathing is filled with gases. It means that gases fill all the space they enter. Below, we have highlighted the properties of gases. Let’s have a look- 

  • Compressibility

Gas particles contain huge spaces between them. If pressure is applied, this space can be lowered down, and the particles can come a little closer. As a result, the gas volume is hugely affected. Another way to compress gas is by decreasing the temperature. If the temperature falls, there are generally fewer gas particles. 

  • Expansibility

Every time pressure is induced on the gases, they contract. However, if this pressure is not applied, the gas expands.

  • Diffusibility

The gas molecules are in perpetual motion at extremely high velocity. A large amount of space exists between molecules. In case two different gases are mixed, the particles of both seamless blends. As a result, this gas mixture remains homogeneous. 

  • Low Density

As mentioned, gases have huge intermolecular spaces; when compared to their respective masses, gases have large volumes leading to low density. 

  • Pressure Exertion

Solids excrete pressure in the downwards direction, whereas; liquids excrete pressure in the downwards and side directions. However, gases excrete pressure in all directions, for example, gas balloons. 

What are Noble Gases?

Noble gases are inert or non-reactive elements present in the Group 18 of the periodic table. The first element is Helium He, followed by Neon Ne, Argon Ar, Krypton Kr, and Radon Rn. Even though the noble gas elements are considered inert, after 1962, chemists and scientists were able to form compounds out of a few elements, especially Xenon. 

But since the reactions are limited and need to be performed only under certain conditions, they are also called noble. Out of these five elements, Radon is considered a reactive element, while Krypton and Xenon aren’t available in too much concentration in the atmosphere. Therefore, they are also known as rare elements. 

These noble gases are present between the most electronegative group, Group VIIA of the Halogen elements and the highest electropositive element group or Group IA. 

Physical Properties of Noble Gases

Here are the properties of noble gases. Let’s have a look- 

  1. The rare gases are colourless and do not have any odour prevalent in other gaseous elements. 
  2. Atomic radii of these gases are the largest because the electrons in the last subshell repel each other and increase the radii slightly. 
  3. When heat is subjected to the noble elements in a solid or liquid state, they can change state much earlier than other elements. This is because no valence shell is present, and the Vander Waal forces weakly hold the last orbit electrons. 
  4. Another major exciting fact about the physical appearance of the noble gas elements is that they can be liquified easily where the tendency increases down the group.

Conclusion 

With this, we come to today’s discussion about the properties of gases. The properties of gases are one of the most important and interesting topics of Chemistry. In this Study material notes on properties of gases, we studied gases in length. We also covered other essential gases, properties of gases, and other related topics such as noble gases in detail. We hope the properties of gases study material must have helped attain a greater understanding of this topic.