Why Are Gases Important in Everyday Life?
Gases are the state of matter in which molecules are the most loosely packed as compared to solids and liquids. The molecules in gases have the highest movement and vibrations out of all the states of matter (Solids, Liquids, and Gases) as they can freely move in the space available. Gases also have high kinetic energy because of this movement and vibration which helps them to overcome the intermolecular force of attraction. Out of all the three states of matter, gases have the least density. This low density is the result of the low force of attraction between the molecules in gases. The molecular structure of different states of matter can be seen in the following image:
Structure of Different States of Matter
Examples of Gases
Examples of gases are Oxygen, Carbon Dioxide, water vapours, Natural gas, Nitrogen, etc.
Fun Facts About Gases for Kids
Gases don’t have a fixed volume. They expand or compress to take the volume of the container in which they are stored.
Gases don’t have any fixed shape. As mentioned earlier, they take the shape of their parent container.
Gases can be easily compressed because of the huge space available between the molecules of gases.
Unlike solids or liquids which don’t necessarily mix with themselves sometimes, gases can easily mix with one another.
If gases are compressed too much, then they are converted to liquids, on further compression they change their state to solids.
What is Natural Gas?
Natural gas is a naturally occurring gas. It is extremely valued for its fuel capabilities. It is a mixture of various gases, hydrocarbons, and alkanes. Carbon dioxide, nitrogen, and helium can also be traced in natural gas. It is a non-renewable resource and a fossil fuel and therefore, we must be very careful with its usage.
Fun Facts About Natural Gas for Kids
Natural gas is an odourless gas; however, Methyl Mercaptan is added to odorize it. This helps in the detection of leaks.
Natural gas is the cleanest-burning hydrocarbon.
Power plants that operate on natural gas emit less than one-tenth of the pollutants released by the power plants that operate on coal.
When natural gas is liquified for transportation, it becomes a colourless, clear, and non-toxic liquid.
Liquified Natural Gas (LNG) does not exhibit fuel-like properties as it is not explosive and cannot burn.
Learning by Doing
1) Which of the following is a gas:
Carbon dioxide
Oxygen
Nitrogen
All of the above
Ans: d) All of the above
2) Which odorizer is added in natural gas to add odour to it?
Oxygen
Methyl mercaptan
Water
Carbon monoxide
Ans: b) Methyl mercaptan
Solved Questions
1) Which state of matter has the least density?
Ans: Gases have the least density among all three states of matter.
2) Which state of matter has the highest density and why?
Ans: Solids have the highest density among all three states of matter because the force of attraction between molecules is extremely high and they are tightly packed together.
Summary
There are three states of matter. They are solids, liquids, and gases. Gases are the least dense of the three and have very high intermolecular space. They have high kinetic energy and thus the force of attraction between the atoms is extremely less. They are highly compressible and can be converted into liquids and solids. They don’t have any fixed volume or shape, their volume and shape are determined by their parent container.
FAQs on Fascinating Facts About Gases
1. What are the key properties that define a gas?
Gases are a state of matter with several unique properties. Unlike solids or liquids, gases are defined by the following characteristics:
No Fixed Shape or Volume: Gas particles are far apart and move randomly, allowing them to take the shape and volume of any container they occupy.
High Compressibility: Due to the large empty spaces between particles, a gas can be easily compressed into a smaller volume.
Low Density: Gases have a much lower density compared to liquids and solids because their particles are spread out over a large area.
Ability to Mix Evenly: Gas particles move constantly and independently, allowing different gases to mix together completely and evenly in a process called diffusion.
2. What are some common examples of gases we encounter?
We are surrounded by gases every day. Some of the most common examples include Oxygen (O₂), which is essential for breathing; Nitrogen (N₂), which makes up about 78% of Earth's atmosphere; and Carbon Dioxide (CO₂), which we exhale and plants use for photosynthesis. Other examples are Helium (He), used to fill balloons, and Methane (CH₄), the main component of natural gas used for cooking and heating.
3. How can a gas be changed into a liquid or a solid?
A gas can be transformed into a liquid or solid by changing its temperature and pressure. To convert a gas into a liquid (a process called condensation), you must reduce the kinetic energy of its particles. This is typically done by cooling the gas and/or applying pressure to force the particles closer together. If you cool the resulting liquid further or apply even more pressure, it can turn into a solid (freezing).
4. What makes gases unique compared to solids and liquids?
The primary factor that makes gases unique is the behaviour of their particles. In solids, particles are locked in a fixed position. In liquids, particles can slide past one another but remain in contact. In gases, however, the particles have so much energy that they overcome the forces holding them together. This results in particles that are far apart and move freely and randomly. This freedom of movement is why gases have no fixed shape or volume and can be easily compressed, unlike solids and liquids.
5. Why do gases have the weakest forces between their particles?
Gases have the weakest intermolecular forces of attraction because their particles possess very high kinetic energy. This high energy causes the particles to move rapidly and overcome the weak attractive forces that would otherwise pull them together. The vast distances between the particles in a gas also contribute to making these forces of attraction insignificant compared to those in liquids and solids, where particles are much closer to each other.
6. Why does a gas expand to fill any container it is in?
A gas expands to fill its container because its particles are in constant, random, and high-speed motion. They travel in straight lines until they collide with other particles or the walls of the container. Since there are no strong forces holding them together, they continue to spread out indefinitely until they are stopped by a boundary. This continuous movement ensures that the gas particles distribute themselves evenly throughout the entire volume of the container, regardless of its size or shape.
7. Are all gases invisible?
No, this is a common misconception. While many common gases like oxygen, nitrogen, and carbon dioxide are colorless and therefore invisible to the human eye, some gases have distinct colors. For example, chlorine gas (Cl₂) is a pale greenish-yellow, and nitrogen dioxide (NO₂), a common air pollutant, is a reddish-brown gas. The visibility of a gas depends on its chemical properties and how it interacts with light.
8. How is the pressure of a gas created?
Gas pressure is the result of the collective force of its particles colliding with the inner surfaces of its container. Each individual particle is tiny, but there are billions of them moving at high speeds. When they strike the container walls, they exert a small force. The total pressure is the combined effect of all these continuous collisions over a specific area. If you increase the number of particles or increase their speed (by heating the gas), the number and force of collisions will increase, leading to a higher pressure.
