A gas is a form of matter that does not have a defined shape or volume. Gases can consist of a single element, such as hydrogen gas (H2); they may also be a compound such as carbon dioxide (CO2) or even a mixture of several gases such as air.
Key Takeaways: 10 Gases and Their Uses
A gas is a form of matter that lacks either a defined shape or a define volume. In other words, it fills a container and takes its shape.Any form of matter that exists as a solid or liquid also takes the form of a gas. Matter changes into a gas when temperature increases and pressure decreases.Gases can be pure elements, compounds, or mixtures. They can contain solitary atoms, ions, and compounds.Gases have many uses. Oxygen is one of the most important gases for humans. Carbon dioxide is one of the most important gases for all life on Earth because plants need it for photosynthesis.
Here is a list of 10 gases and their uses:
Oxygen (O2): medical use, weldingNitrogen (N2): fire suppression, provides an inert atmosphereHelium (He): balloons, medical equipment Argon (Ar): welding, provides an inert atmosphere for materialsCarbon dioxide (CO2): carbonated soft drinksAcetylene (C2H2): welding Propane (C3H8): fuel for heat, gas grillsButane (C4H10): fuel for lighters and torchesNitrous oxide (N2O): propellant for whipped topping, anesthesia Freon (various chlorofluorocarbons): coolant for air conditioners, refrigerators, freezers
Monatomic, Diatomic, and Other Forms
The monatomic gases consists of single atoms. These gases form from the noble gases, such as helium, neon, krypton, argon, and radon. Other elements typically form diatomic gases, such as oxygen, nitrogen, and hydrogen. A few pure elements form triatomic gases, such as ozone (O3). Many common gases are compounds, such as carbon dioxide, carbon monoxide, nitrous oxide, propane, and freon.
A Closer Look at Gas Uses
Oxygen: In addition to its industrial uses, oxygen gas is essential for respiration in most living organisms. Humans breathe it. Plants release oxygen as a by-product of photosynthesis, but also use it for respiration.Nitrogen: Most of the Earth's atmosphere consists of nitrogen, our bodies can't break the chemical bond between the atoms and use the element from the gas. Nitrogen gas, sometimes mixed with carbon dioxide, aids in food preservation. Some incandescent light bulbs contain nitrogen gas instead of argon. Nitrogen gas is a good fire suppression agent. People sometimes inflate tires with nitrogen instead of air because it avoids problems caused by water vapor in air and excessive gas expansion and contraction with temperature changes. Nitrogen gas, sometimes with carbon dioxide, pressurizes beer kegs. Nitrogen gas inflates air bags in automobiles. It's used for intentional asphyxiation as a form of euthanasia.Helium: Helium is abundant in the universe, but relatively rare on Earth. Most people know helium balloons are less dense than air and float. But, balloons are a minor part of commercial helium use. It's used in leak detection, pressurizing and purging gas systems, and welding. Silicon, germanium, titanium, and zirconium crystals are grown in a helium atmosphere.Carbon dioxide: Carbon dioxide makes soft drinks bubbly and makes the news as a greenhouse gas. It has many important uses. Plants need oxygen to perform photosynthesis. Humans need carbon dioxide too. It acts as a signal, telling the body when to breathe. Carbon dioxide forms bubbles in beer and sparkling wine. It's a common food additive and swimming pool chemical used to regulate acidity. Carbon dioxide finds use in fire extinguishers, lasers, and dry cleaning.
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