Meaning of gas in Science

A gas is one of the three states of matter, the other two being liquid and solid. Many elements exist as gases at standard temperature and pressure, while many other elements and compounds can become gases under certain circumstances. Here is a list of gases.

Elemental Gases

These are the elements that exist as gases at standard temperature and pressure. When the pressure is changed and is higher or lower, or when the temperature is changed and is higher or lower, then the element may exist in a different form such as in liquid form or solid form.

Hydrogen (H)
Nitrogen (N)
Oxygen (O)
Fluorine (F)
Chlorine (Cl)
Helium (He)
Neon (Ne)
Argon (Ar)
Krypton (Kr)
Xenon (Xe)
Radon (Rn)

Pure and Mixed Gases

Pure gases can take several different forms. They might be made up of individual atoms, such as neon, atomic gases or noble gases. Oxygen is also a pure gas because it is made of one type of item; however, it is an elemental molecule.

Pure gases may also be compound molecules, which are comprised of a bunch of different atoms. For example, carbon dioxide would be considered a pure gas but it is also a compound molecule.

Mixed gases, on the other hand, consist of more than one kind of pure gas. In the Earth's atmosphere, for example, there are a wide mix of different gases including oxygen and other atoms that are released.

Some examples of pure gases and mixed gases include:

Acetylene
Air
Ammonia
Arsine
Benzene
Boron Trifluoride
Butadiene 1, 3
Butane
1-Butene
Carbon Dioxide
Carbon Monoxide
Diborane
Ethane
Ethylene
Ethylene Oxide
Germane
Halocarbon-14
Halocarbon-21
Halocarbon-22
Halocarbon-23
Halocarbon-32
Halocarbon-116
Halocarbon-134A
Halocarbon-218
Halocarbon-C318
Hexane
Hydrogen Bromide
Hydrogen Chloride
Hydrogen Sulfide
Isobutane
Isobutylene
Methane
Methanol
Methyl Chloride
Nitric Oxide
Nitrogen Dioxide
Nitrogen Trifluoride
Nitrous Oxide
Pentane
Phosphine
Propane
Propylene
Silane
Silicon Tetrachloride
Sulfur Dioxide
Sulfur Hexafluoride
Trichlorosilane
Tungsten Hexafluoride
Vinyl Chloride

Toxic Gases

Toxin gases are those that can cause harm when they are breathed in or when people are exposed to them. In some cases, breathing in a toxic gas, even for a few seconds, can result in death. In other instances, breathing in a toxic gas just might make you feel sick or light headed, or breathing in the toxic gas might not have an effect until you've breathed in a sufficient amount that it builds up in your blood.