In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals.

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Can an atom join with more than 8 other atoms?

Is it possible for an atom to combine with 8 other elements of same or other type? If yes, then please give some examples. If no, then what could be the possible reason for it?
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Reading number of outer shell electrons and other properties from periodic table?

How can one read from the periodic table the number of outer shell electrons that an atom has, to predict how these atoms will make bonds with other atoms? For example to see that hydrogen ($\ce{H}$) ...
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Stability of half and fully filled orbitals [duplicate]

1) My textbook tells me that chromium's electronic configuration is $\ce{[Ar]}\space 3d^5 4s^1$ instead of $\ce{[Ar]} \space 3d^4 4s^2$, as fully filled and half filled orbitals have more stability. ...
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How are electronic configurations determined experimentally?

Despite the ubiquitous usefulness of electronic configurations (of elements) in explaining their behavious I have not been able to find out exactly how the configurations are determined. Is there ...
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Energy of photons emitted by de-excitation of electrons

When an electron of an atom returns from an excited state to the ground state, it emits energy in the form of a photon. How does the change in energy level compare to the energy of the emitted photon? ...
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what is SPDF configuration?

Recently in my chemistry classes the teacher spoke about SPDF configuration and then said that we'll be taught about it in higher classes. But I'm sorta curious to know that what is SPDF ...
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How to find the highest and lowest oxidation state of transitional metal

My teacher taught me the formulas 'nS' and 'nS+(n-1)d' to find the highest and lowest oxidation state of transition elements. He gave the example of $\ce{Mn}$ and showed that the numbers were +2 and ...
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Azimuthal Quantum Numbers

Why do azimuthal quantum numbers have a value lesser than Principal Quantum number. example- if n=1 it will have subshell "s" as 0
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Is it possible to predict the lines in the atomic emission spectrum of Na?

The atomic emission spectrum for sodium ($\ce{Na}$) is completely dominated by a line in the range of yellow, about $590~\mathrm{nm}$ (to be more precise, it's a doublet). Here is how it looks like: ...
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Is one electron spin preferred over the other in filling of orbitals? [duplicate]

When filling an orbital diagram of an atom, usually the up-spin is filled first and then the down-spin. For example, for Nitrogen, we have : But in a model in which up-spin electron is preferred ...
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Hypervalency and the octet rule

I realize that the octet rule is more a suggestion than a rule, and that it applies mainly to non-transition metal compounds. Still, compounds that don't have an octet, like $\ce{BH3}$, tend to ...
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MO for $N_2^{2-}$

Could someone please show me the MO diagram for $\ce{N_2^{2-}}$? What I did was since N has 5 valence $\ce{e^{-}}$, then $\ce{N_2}$ must have 10, and $\ce{N_2^{2-}}$ must have 12. And $\ce{N}$ has $s$ ...
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Atomic number $Z$

If electrons were spin-$\frac {3}{2}$ instead of spin-$\frac {1}{2}$ , what would be the atomic number $Z$ for the first noble gas ?
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How does radiation facilitate the formation of tetravalent iron?

In reading the article abstract What Oxidation State of Iron Determines the Amethyst Colour?, the author states that in regards to the gemstone amethyst, from clear quartz: The crystal was ...
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How many electrons does each shell hold?

why some times 2nd shell onward it can hold 8 electrons and other times it is like they can hold K2 L8 M18 N32? when do i have to use first method(K2 L8 M8 N8) and when to use second method (k2 L8 ...
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Quantum Numbers and Ions

How do quantum numbers change for ions? A sample question: Give the set of four quantum numbers that could represent the electron lost to form the Rb ION from the Rb atom. The answer given is n=5; ...
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Why does this reaction take place in terms of electronic structure?

I need to know, in terms of electronic charge - the electrophiles and nucleophiles involved - how the electronegativity of the potassium and hydrogen atoms alongside the hydroxide and H+ ions result ...
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Second ionization potential of Gadolinium

I notice that Gd has a second ionization potential which is significantly higher than would be expected from the general trend in the lanthanides (see this paper p. 945 for a graph). What is the ...
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What is the electronic configuration of Fe(II) ion?

The electronic configuration of Fe is 1s2 2s2 2p6 3s2 3p6 4s2 3d6. So after removing two electrons the configuration becomes: 1s2 2s2 2p6 3s2 3p6 3d6 But why cant the electrons rearrange themselves ...
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A unique demo for singlet oxygen?

I have long known that mixing bleach and peroxide produces oxygen gas: $$\ce{NaOCl + H2O2 -> O2 + H2O + NaCl}$$ However I only recently learned that the specific form of oxygen produced by the ...
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abbreviations in electronic configurations

I am teaching my students how to write the electronic configuration of the elements of the periodic table. Thus, following the rules on how to fill the orbitals, the electronic configuration of iron ...
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degeneracy and Mendeleev table [closed]

A very basic question. When we construct Mendeleev table we can think of adding one electron at a time, filling one by one the electronic states, that are numbered by well known quantum numbers (using ...
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154 views

Hybridization of the oxygen in furan?

I fail to understand why the hybridization of oxygen in furan is $\ce{sp^2}$. I think that since there are 2 bond pairs and two lone pairs so it should be $\ce{sp^3}$ hybridized? Is it to do with the ...
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sp² hybridized orbital

I do not understand why and how an atom with $\ce{sp^2}$ hybridization has only one p orbital?? For example in pyridine why is the lone pair of nitrogen not counted as a pi electron.
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What does this property of transition metals mean? [duplicate]

what does it mean: "Transition metals either have incompletely filled d subshells or readily give rise to cations that have incompletely filled d subshells. I don't understand the portion starting ...
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60 views

Electron Configuration of an element with no. of electrons > 18

Let's say that we have an element, say $\ce{Ca}$. According to law, the last shell should contain only upto 8 e-. Hence, electronic configuration of $\ce{Ca}$ would be 2,8,8,2. But, according to the ...
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Why does the electron configuration for some elements not follow the diagonal rule?

I'm doing a high-school assignment, and I came across a question that I didn't quite understand. Explain how the electron configurations for the following elements do not follow the diagonal ...
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Why is it that weak bases usually contain a Nitrogen?

Why do weak bases usually contain a nitrogen, I know there are two electrons on top for a bond of H but why is it mostly nitrogen? I know there are other elemental bases too but why do I keep seeing ...
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Is it possible to calculate atomic radius with electron configuration?

I need to know whether is it possible to calculate the atomic radius according to the number of electrons and electron configuration. Or is there any way to calculate the atomic radius using common ...
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Why are d-orbitals required/used for hypervalent molecules (where the central atom has expanded its octet) [duplicate]

Period 2 elements like carbon, oxygen and nitrogen cannot expand their octet because they cannot make use of d orbitals in that energy level (they don't exist). However, period 3 elements like sulfur ...
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Why the second ionization energy of helium is greater than the first? [closed]

maybe because the first electron has a lower energy. Why does this happen?
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80 views

What is the usage of orbitals more complex than f orbitals?

Every high school learner, in each corner of the world, faces the lesson History of Atom during his courses, just as I did. We learned about s,p,d and f orbitals, though there were no signs of ...
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75 views

How to find the possible valence states of elements in the lower end of the d block and the f block?

For silver, why don't the electrons in the 4d orbital move to the 5p orbital? Is it possible for any elements to move their electrons between $n$d and $(n+1)$p orbitals? When the f orbital is ...
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32 views

Why don't electrons pair up in an oxygen radical?

In an oxygen radical (produced by the break down of O3 for instance), there are 2 unpaired electrons in the outermost subshell which make the molecule unstable. Why don't these electrons pair up which ...
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Some abnormalities in the Periodic Table

I observe some elements like $\ce{Cr}$ and $\ce{Cu}$. Some of them have strange oxidation numbers that don't really fit the purpose of making the element as stable as possible. Just Chromium, for ...
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What is a good (small) model system for ligand metal charge transfer practises?

I am looking for an easy to calculate model system in which I could see a ligand metal charge transfer. Basically I am looking for a model complex, that might have the metal/ligand in different ...
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How can I interpret the colour of flames in terms of spectral series?

I saw different colors of fire burning different metals. But how does this work? The Balmer series requires electrons to drop back down to n = 2. But, not all alkali metals have empty space in their ...
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Form the oxides of the element Z=39

Its electronic configuration is $4d^15s^2$ so in normal state it has valence=1 and in energetic state, valence=2 (because our teacher said we count only the electrons in the outer shell firstly) and ...
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119 views

What determines how favorable (exothermic) is the electron affinity of a certain element?

(Favorable means how exothermic a reaction is, more favorable= more exothermic) There are some abnormalities in the trends of how favorable the electron affinity is. From Al to Cl, the ...
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Electron shell, how do they know it?

I started to learn Chemistry with something like Hydrogen having 1 electron in the first shell, Oxygen having 2 electron in the first shell and 6 electron in the second shell... But I don't really ...
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59 views

Find the valences of Z=26

I've tried this: But its hows that the valence of Fe in normal state is 4, when in the periodic table it isn't. Why does this happen? Can you show me the answer with configuration formula in the ...
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A way to calculate orbital energy of an electron

Maybe this is just not included in my course, but I still wonder how to calculate the binding energy of an electron .at a certain electron orbital. Intuitively,The ionization energy of an element ...
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Which electrons will be taken when oxidations take place and how does the resulting orbital diagram look like?

In detail, what I really mean is which electron in which orbital is being taken when a oxidation happen? Let me give a example: chromate ion(II) Two electrons are taken but from which orbital:
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Properties of f-orbitals

I am not a Chemist, but I took enough undergraduate Chemistry classes to understand the basic properties of s, p and d orbitals and how the behaviour of electrons contributes to different kinds of ...
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how many electrons are in the second subshell of this element?

first of all sorry if I have some mistakes in my "chemistry words", I'm Iranian and I know the Persian terms but only some of the English ones. So suppose we have an element (x) with the atomic ...
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Why is there an exponent 4 after the brackets in sp3?

My professor wrote an electron configuration for carbon as: 1s2 (sp3)4 I thought it was just 1s2 sp3 where did the 4 come from?
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How does the radial distribution function of Vanadium differ from that of Calcium and how does this affect the ionic electron configurations?

When Vanadium is ionised it loses the 4s electron first, meaning that it's 3+ ion has a different electron configuration to Calcium despite it being isoelectronic. Can it be explained in terms of ...
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What's the electronic configuration of Nickel and Oxygen in RNiO3 (R=Rare-Earth)?

Nickel's electronic ground state is $\mathrm{3d^8 4s^2}$ (there's a dispute on this, but let's not worry about it for now). Oxygen's is $\mathrm{2s^2 2p^4}$. In a Rare-Earth based Nickelate with ...
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Doesn't the fact that the lone pair on the nitrogen in amides occupy a p orbital contradict Hund's rules?

Since the $\ce{sp^2}$ hybridized orbitals are lower in energy than the p orbital shouldn't the $\ce{sp^2}$ orbitals fill first? Why is this not the case - two electrons fill the p orbitals while all ...
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Difference between shells, subshells and orbitals

What are the definitions of these three things and how are they related? I've tried looking online but there is no concrete answer online for this question.