How can neon react with other elements

The octet rule

The noble gases are absolutely inert

The chemists of past centuries have already established that noble gases behave completely differently than other chemical elements. They do not react at all, not even with concentrated acids or when heated strongly with pure oxygen. Because of this inertia, the gases helium, neon, argon, krypton, xenon and radon have also been called "noble gases", in analogy to the "noble metals" silver, gold and platinum, which are also very inert. Compared to the noble gases, however, the noble metals are quite reactive. There are some compounds from silver, even gold and platinum can react with other substances under certain circumstances. The noble gases, on the other hand, do not react at all, with very few exceptions. An overview of the few noble gas compounds can be found on the Wikipedia page "Noble gas compounds".

The interesting behavior of the noble gases could not be explained with Dalton's spherical particle model, Thomson's raisin cake model or Rutherford's core-shell model. This was only possible with the advent of the Bohr shell model.

The noble gas state

Based on Bohr's shell modelall noble gases have an outer shell that is fully occupied with electrons.

The helium possesses two Electrons on the K shell, which is fully occupied with it. The second noble gas, neon, possesses eight Electrons on the L-shell, which is also fully occupied. The third noble gas also has argon eight Electrons on the M-shell, which is also fully occupied.

For experts:

As such, the M-shell can hold 18 electrons, but if we want to deal with this topic, we get into the complex realm of transition metals and have to use the orbital model. With these elements, not only the s and p orbitals are occupied, but also the five d orbitals, into which another 10 electrons fit. For levels 9 and 10 or EF, for which these pages are primarily written, this is certainly not appropriate. The d orbitals are not discussed even in levels Q1 and Q2, but only in chemistry studies, when the electron configuration of transition metals is dealt with.

For super experts who still want to read on:

In the orbital model, the L-shell is represented by an s-orbital and three p-orbitals. Two electrons fit into each orbital, so a total of eight electrons can be accommodated on the L-shell.

The M shell is represented in the orbital model by one s, three p and five d orbitals; here, too, two electrons fit into each orbital. If you add everything up, you get 18 electrons for the M-shell.

The N-shell is also represented by one s, three p and five d orbitals. However, the s-orbital and the three p-orbitals are on an energetically lower level than the five d-orbitals of the M-shell. That means, when the orbitals of an atom are occupied with electrons, the s- and p-orbitals of the N-shell are "turned" first. Only when these orbitals are occupied by two electrons can the five d-orbitals of the M-shell be occupied.

Well, that should be enough for the super experts at first. That goes far beyond the school material.

The following applies to all noble gases: The outer shell of the atoms is fully occupied. The atoms of the other elements have an outer shell that is not fully occupied with electrons, they lack electrons. Therefore, a complete occupation of the outer shell is also referred to as a noble gas state.

Noble gas state

When the atoms of an element have a fully occupied outer shell, this is called the noble gas state.

The octet rule

But why are the noble gases so inert? The answer to this question is formulated almost by itself: Obviously the noble gas state, i.e. the possession of a fully occupied outer shell, is something that "satisfies" the noble gases. With their fully occupied outer shell, they no longer have any need to accept or release electrons. You have reached the optimal (energetically most favorable) state.

Now what about the other elements, sodium and chlorine for example?

Chlorine has seven electrons on its outer shell. If it had one more electron, it would have just as many outer electrons as the noble gas argon. Oh, what would that be great! One more electron and you would be a noble gas! Or at least similar to noble gas. And it is precisely for this reason that chlorine strives to take up an electron. It "wants" to reach the noble gas state of argon. Of course you can't pick up an electron if you sit around doing nothing. You have to be a little active. Chlorine becomes quite active, the element undergoes all sorts of chemical reactions to fill up its outer shell.

And that brings us to the octet rule, which says exactly what I have just described with somewhat loose words:

Octet rule

All elements strive to have a fully occupied outer shell and thereby achieve the inert gas state.

Let's apply this octet rule to the element sodium. Sodium has an electron on its outer shell. So the sodium atom would have to take up seven electrons to get into the noble gas state.

But no, it's a lot easier.

Now imagine the four outer spherical clouds of the sodium atom, which are occupied by only one electron. What does it reveal? Right, the second outer shell, the four spherical clouds of which are completely occupied with electrons. So the easiest way for sodium and the other alkali metals to reach the noble gas state is when they release their outer electron. Then the outer shell falls away, and the second outer shell with eight electrons (or with lithium then with two electrons) becomes the new outer shell. Done - the inert gas state has been reached.

The chemical bond as a solution to the noble gas problem

The only problem is now: the sodium "wants" to give up an electron, but has to find a partner who can take the electron from it. There are three ways to achieve this goal.

Way 1: metallic bond

Many sodium atoms combine and give off their outer electrons to an "electron gas" that is located between the sodium atomic cores. Such a procedure leads to the metallic bond (see there).

Path 2: electron pair binding

A sodium atom combines with another atom, which also has a single cloud of spheres. The two simply occupied spherical clouds overlap, and a common spherical cloud, occupied by two electrons, is formed. This procedure leads to the covalent bond (electron pair bond; see there). However, there are hardly any covalent compounds of sodium because the first way and the third way are much cheaper.

Way 3: Ionic Bond

A sodium and a chlorine atom join forces. The sodium atom gives up its electron, the chlorine atom accepts the electron, and both are "happy". The sodium atom becomes the positive sodium cation with neon configuration, the chlorine atom becomes the negative chloride anion with argon configuration. Both elements have thus reached the noble gas state. The positive and negative ions attract each other - and we already have the ionic bond (see there).

See the following pages for details on these three types of bindings. I will not go into the intermolecular bonds (van der Waals, dipole-dipole and hydrogen bridge bonds) at this point.

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Atomic structure - octet rule - ionic bond - electron pair bond - metal bond - electronegativity