We explain that what are some examples of gases? Gases are the substances that represent the state of matter of the same name. They are constituting the atmosphere and forming in biological processes.
Natural State of Gases
Gases can be found in their pure state or as a mixture . For example, natural gas that is extracted through fracking for use as fuel consists of Methane CH 4 , Ethane C 2 H 6 and Propane C 3 H 8 .
Another example is Air, which is a mixture of numerous gases in certain proportions . This mixture favors the processes of life and produces a protection against cosmic events.
Air is made up of: 79% Nitrogen, 20.9% Oxygen, 0.1% Argon and other minor percentages of other gases.
Substances that exist as gases
Pure substances that are found in gaseous form under atmospheric conditions can be classified into three categories: Noble Gases , Chemical elements of diatomic molecule , and Chemical compounds .
The Noble Gases are the chemical elements that have eight electrons in their last shell, so they do not have the need to create bonds with the atoms of other elements. They occur in monatomic form (a single atom). They are Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe).
The elements of a diatomic molecule (with two atoms) are Hydrogen (H 2 ), Nitrogen (N 2 ), Oxygen (O 2 ), Fluorine (F 2 ) and Chlorine (Cl 2 ). Its molecules have reached stability by joining two atoms of themselves.
The chemical compounds that exist in the environment as gases are methane (CH 4 ) , the carbon dioxide (CO 2 ) , the carbon monoxide (CO) , the hydrogen sulfide (H 2 S) , the sulfur dioxide ( SO 2 ) , Sulfur Trioxide (SO 3 ) , Nitrogen Oxides or NOx’s .
General Characteristics and Properties of Gases
Gases have their molecules widely separated , moving fast, energetically. Their cohesion is low , and they cannot be kept fixed in one place.
Being contained in a container, gases occupy a volume, determined by its shape .
The density of gases is generally very small, much less than that of a liquid, of course. For example, the Density of air is 1,225 Kg / m 3 . It is, in fact, a very small quantity: just over 1 kg of air in each cubic meter.
When heated , their molecules have a higher kinetic energy , so they will strike more frequently inside the container. This results in increased pressure.
When they cool enough , their molecules stop having high kinetic energy, so they are ordered until they reach the Liquid state. This transformation from a gaseous state to a liquid state is called Condensation . It also results in a lower Pressure.
Gases have a very small Viscosity . If a Pressure is printed on them , the gases are able to flow and thus they are directed from point A to point B.
Of all gases, only oxygen is essential for life .
The behavior of gases is governed by the Gas Laws, which are postulates that link the three main properties: Pressure, Volume and Temperature . Based on the gas laws, it is possible to calculate any of these three variables, at the beginning and at the end of a thermodynamic process.
Examples of Gases
- Helium (He)
- Neon (Ne)
- Argon (Ar)
- Krypton (Kr)
- Xenon (Xe)
- Hydrogen (H 2 )
- Nitrogen (N 2 )
- Oxygen (O 2 )
- Fluorine (F 2 )
- Chlorine (Cl 2 )
- Methane (CH 4 )
- Carbon Dioxide (CO 2 )
- Carbon Monoxide (CO)
- Hydrogen Sulfide (H 2 S)
- Sulfur Dioxide (SO 2 )
- Sulfur trioxide (SO 3 )
