Okay, helium balloons are light...but they"re not that light! The fanciful image below serves to make the allude that helium is among the lightest elements. Helium belongs come a group of aspects called the noble gases.

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Figure $$\PageIndex1$$: Helium is among the lightest aspects in the routine table.

## What space Noble Gases?

Noble gases space nonreactive, nonmetallic elements in team 18 that the routine table. As you deserve to see in the periodic table in the figure below, noble gases incorporate helium $$\left( \ceHe \right)$$, neon $$\left( \ceNe \right)$$, argon $$\left( \ceAr \right)$$, krypton $$\left( \ceKr \right)$$, xenon $$\left( \ceXe \right)$$, and also radon $$\left( \ceRn \right)$$. Every noble gases room colorless and odorless. They likewise have short boiling points, which describes why they space all gases at room temperature. Radon, in ~ the bottom that the group, is radioactive, so that constantly decays to various other elements.

Figure $$\PageIndex2$$: Noble gases are in group 18 of the regular table, in this instance the red tower on the far right.

## smashville247.netical nature of Noble Gases

Noble gases space the the very least reactive that all recognized elements. Your outer energy levels space full since they each have actually eight valence electrons. The only exemption is helium, which has just two electrons. However helium additionally has a complete outer energy level, since its only power level (energy level 1) can hold a maximum of 2 electrons. A complete outer power level is the many stable plan of electrons. As a result, noble gases cannot become an ext stable by reaction with other elements and also gaining or shedding valence electrons. Therefore, noble gases room rarely involved in smashville247.netical reaction and virtually never type compounds with other elements.

## Noble Gases and also the Octet Rule

Because the noble gases space the the very least reactive of every elements, their eight valence electron are provided as the standard for non-reactivity, and to define how other facets interact. This is stated as the octet ("group the eight") rule. Follow to this rule, atoms reaction to type compounds that enable them to have actually a group of eight valence electrons prefer the noble gases. For example, sodium (with one valence electron) reacts through chlorine (with seven valence electrons) to form the stable compound sodium chloride (table salt). In this reaction, salt donates an electron and chlorine accepts it, offering each element an octet that valence electrons.

## Some supplies of Noble Gases

Have you ever before hadhelium balloons like those in the elephant image? uneven a balloon filled through air, a balloon filled v helium requirements to it is in weighted under so that it won"t to rise away—although you don"t have to use one elephant!

Early incandescent light bulbs, favor the one pictured in the figure below, didn"t last really long. The filaments quickly melted out. Return air to be pumped out of the bulb, that wasn"t a finish vacuum. Oxygen in the tiny amount that air staying inside the light bulb reacted with the steel filament. This corroded the filament and caused dark deposits on the glass. Pour it until it is full a light bulb with argon gas prevents these problems. That"s why modern light bulbs are filled v argon.

Figure $$\PageIndex3$$: modern light bulbs space filled v the noble gas argon to stop corrosion that the filament inside.

Noble gases are additionally used to fill the glass tube of lighted indications like the one in the number below. Return noble gases space smashville247.netically nonreactive, your electrons have the right to be energized by sending out an electric present through them. Once this happens, the electrons jump to a greater energy level. When the electrons return to their original energy level, they offer off power as light. Different noble gases give off light of various colors. Neon gives off a reddish-orange light, like the native "Open" in the sign below. Krypton provides off violet light and xenon gives off blue light.

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Figure $$\PageIndex4$$: indicators like this one space filled v nobles gases prefer neon or xenon, which give off light once energized.