What are Noble Gases?
In chemistry, the noble gases refer to the chemical elements that belong to Group 18 of the periodic table. This family of elements can be found on the far right end of the periodic table, in the last column. Noble gases are referred to as inert gases because they will not react with any other element on the periodic table. These gases are the least reactive gases because they have a full outer layer of valence electrons. This means that they will not form a bond with other elements on the periodic table.
Noble Gases List
There are seven elements that are classified as noble gases. These elements are:
- Helium: The symbol for helium is He. Its atomic number is 2 and helium is a naturally occurring gas in the atmosphere of Earth as well as on other planets.
- Neon: The symbol for neon is Ne. Its atomic number is 10 and neon is a naturally occurring gas in the air.
- Argon: The symbol for argon is Ar. Its atomic number is 18 and argon is a naturally occurring gas in the air.
- Krypton: The symbol for krypton is Kr. Its atomic number is 36 and krypton is a naturally occurring gas in the air.
- Xenon: The symbol for xenon is Xe. Its atomic number is 54 and xenon is a naturally occurring gas in the air.
- Radon: The symbol for radon is Rn. Its atomic number is 86 and radon is a radioactive gas that is produced from the decay of heavy metals such as radium.
- Oganesson: The symbol for oganesson is Og. Its atomic number is 118 and oganesson is a man-made radioactive element.
The noble gases that are naturally occurring in the air can be obtained through fractional distillation.
Noble Gases Properties
Noble gases are also referred to as inert gases due to their nonreactivity with other elements. This characteristic of the noble gases is probably the one people remember the most. However, the noble gases also have other properties in common. Remember, the noble gases are in Group 18 of the periodic table and groups in the periodic table can also be referred to as families. This is because a group in the periodic table will exhibit common properties or characteristics. For the noble gases these include low reactivity, low boiling points, high ionization, complete valence shell, very low electronegativities, and they are colorless as well as odorless.
Noble gases have similar physical properties, which is why they are found in a group together. Physical properties refer to the physical characteristics of an element, such as their boiling point, melting point, or solubility. In general, noble gases' physical properties include having a low boiling point and melting point as well as high ionization energies. They also have low interatomic forces.
By using their location on the periodic table, one can make predictions about some of these properties. For instance, their atomic radius can be predicted by using the periodic table. As we move down Group 18, we will notice that their atomic radius will increase because, as we move through each period on the periodic table, the elements increase in the number of electrons they contain. Furthermore, we can make predictions about their melting and boiling points. The element with the lowest boiling point and melting point is at the top of group, helium, and as you move down the groups their melting and boiling points increase. Therefore, the noble gas with the highest melting or boiling point is oganesson.
Chemical Properties refer to the ability of a substance to undergo a chemical reaction. These include color, odor, flammability, and reactivity to name a few. Noble gases have many different types of chemical properties. In general, noble gases are colorless, odorless, nonflammable, and have a low reactivity. Their low reactivity is because they have a complete set of electrons in their outer valence.
The periodic table can help determine how many layers of electrons an element will have. This is made possible by using the period or the rows in the periodic table. For instance, helium will have one layer of electrons, neon will have two layers of electrons, argon will have three layers of electrons, and so on. In order for an element to have a complete outer valence of electrons, the elements must have 2 or 8 electrons. Helium has 2 electrons in its outer layer and the other six have 8.
It was once thought that noble gases do not form compounds but that has since been proven incorrect. While noble gases have a low reactivity due to their full outer shells, they can still form compounds. The noble gases that seem to have minor reactivities are xenon, krypton, and argon. The noble gas that has had the most known bonds is xenon. Xenon will bond with elements that are highly electronegative and xenon seems to have a positive oxidation during these interactions. The elements that will most commonlyform a bond with xenon include oxygen and fluorine.
Chemists can use various methods to separate noble gases and put them in a form where they can be used. The process called fractional distillation, uses heat to separate the gases. This happens because each noble gas has a different boiling point and will separate out at a different time during the heating process. The process where the noble gases are turned into liquids is called liquefication of gases. During this process, a chemist will use high pressure and low temperatures to create condensation.
Noble Gases Applications
Noble gases can be found in our everyday life. There are many uses for noble gases. The list below explains some applications of each noble gas.
- Helium: Helium has many uses because of its low reactivity, nonflammability, and its solubility, particularly in lipids. Helium is used in the breathing gases for SCUBA diving because of its ability to be easily absorbed in lipids. This is done to reduce the effect of nitrogen narcosis. Helium is also used as a lifter for balloons. This is much safer than hydrogen because helium is not flammable.
- Neon: Neon has a low melting and boiling point. Therefore, it is used in cryogenics. Liquid neon has a large refrigerating capacity. Neon is also used in lighting because it is nonflammable, it is used in neon lights.
- Argon: Argon is used to trap unstable compounds so they can be studied. This can happen because of its low reactivity. Argon is also mixed with nitrogen to be used in incandescent light bulbs.
- Krypton: Krypton is used in light bulbs. Krypton is much more efficient for a light bulb because of its ability to be sustained for long periods of time. It is typically found in halogen lamps.
- Xenon: Xenon is used in several types of lamps because of its natural light color. It is used in film projectors and automobile headlamps. Xenon is also used in the medical industry for taking MRIs of the lungs.
- Radon: Radon is a radioactive element and is used in the medical industry for radiotherapy. Radiotherapy is used in the treatment of cancer to treat malignant cells.
- Oganesson: Oganesson is a man-made noble gas and is radioactive. Currently, it does not have any known applications.
The noble gases are found in Group 18 of the periodic table. There are seven that are in the group and, because of their location on the periodic table, one can make predictions about them. For example, they will have an increasing atomic radius as you go down the group. Furthermore, the noble gases have similar physical and chemical properties.
- Low boiling points
- Low melting points
- Low reactivity
- Complete outer valence of electrons
- Colorless, odorless
Because of these physical and chemical properties, the noble gases also have many different everyday applications. For instance, they are often used in the creation of light sources because of their nonflammability. Xenon and radon are also used in the medical industry.
To unlock this lesson you must be a Study.com Member.
Create your account
What are the properties of noble gasses?
Noble gases have similar physical and chemical properties. These include low melting point, low boiling point, colorless, odorless, nonflammable, and low reactivities.
What are the noble gases and what are they used for?
Noble gases are also referred to as inert gases because of there low reactivity. They are used in the medical industry and to conduct electricity. Also, in the production of light sources.
Are noble gases reactive?
Noble gases have a low reactivity. It was once thought that they did not create compounds but that has since been proven incorrect.
Register to view this lesson
Unlock Your Education
See for yourself why 30 million people use Study.com
Become a Study.com member and start learning now.Become a Member
Already a member? Log InBack