Why is duplet or octet of electrons stablizes the atom?

Why is duplet or octet of outermost electrons stablizes the atom?Can somebody tell me???Why can't be 6 or 5 or others? :cry:


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First of all, odd numbers of electrons are not preferred. Atoms like to have electrons in pairs of 2. In their electron orbital, the electrons pair up spinning in opposite directions. Think of you and "your twin" traveling across the globe, but in opposite directions. In the most simple terms that is why odd numbers aren't prefered.

To understand "why" its 8, and not 4,6, etc. you need to understand electron orbitals around the atom. For that, refer to this post and try and root out what you need.


Notice the S + P electrons in ANY period = 8 which is where the "octet" comes from.

the other thing to remember is that,
whilst the are certainly energetic considerations at quantum level with orbitals and octets 'n' that,

when you are considering any particular chemical process,
you need to draw a Born Haber cycle for all the steps,
and consider the enthalpy and entropy contributions for ALL the steps.

You may well find that the most important factor has nothing to do with forming a "stable octet" in many cases.

That's why the Noble gases are in octets!...


the noble gases have that many electrons,
because that's how many they need to match the number of protons in their nucleii!

It's an experimental fact and can't really be pushed on any theoritical grounds. The 3rd role main group elements violate the octet rule frequently.

So how does valency work then?...


Valency == number of valence (outer shell) electrons

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