How Many Valence Electrons Does Argon Have?

Argon, a noble gas, is an element in the periodic table with the symbol Ar and atomic number 18. It was first discovered by Sir William Ramsay and Lord Rayleigh in 1894. Argon is part of the group of elements known as inert gases because they are very unreactive, having a complete valence electron shell.

Valence electrons are those electrons that occupy the outermost shell or energy level of an atom. They are responsible for the chemical properties of atoms, hence the importance of knowing how many valence electrons an atom has. The number of valence electrons varies from one element to another; for example, hydrogen has one valence electron, while oxygen has six.

For argon, we need to look at its electron configuration, which is 1s2 2s2 2p6 3s2 3p6. Argon has three occupied energy levels or shells, with the electrons distributed as follows: two in the 1s orbital, two in the 2s orbital, and six in the 2p orbital, eight in the 3s orbital, and the remaining two in the 3p orbital.

From this arrangement, we can tell that argon has a total of eight valence electrons. This is because the valence electrons are those that occupy the outermost shell, and in argon’s case, the outermost shell is the third one, which has eight electrons. The reason why argon, along with other noble gases, is unreactive is that it already has a full valence shell, making it unlikely to gain or lose electrons in chemical reactions.

Knowing the number of valence electrons that argon has is helpful in understanding its chemical behavior. As mentioned earlier, the fact that argon has a full valence shell makes it very unreactive. This property is used in various applications, such as in welding, where argon is used as an inert gas shield to prevent the weld from oxidizing.

Another application of argon’s unreactivity is in lighting, where it is used in fluorescent lights and streetlights. In fluorescent lights, argon is used to start the discharge of the plasma, which then causes the fluorescence. In streetlights, argon is used in combination with mercury vapor to create a blue-green light.

In conclusion, argon has a total of eight valence electrons, making it very unreactive due to having a full outermost shell. Understanding the chemical properties of elements, including their valence electrons, helps us better understand and utilize them in various applications.

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